


Like Old Times

by Tierfal



Category: Doctor Who
Genre: Adventure, Humor, M/M, Mystery, Romance
Language: English
Status: Completed
Published: 2010-12-05
Updated: 2010-12-05
Packaged: 2017-10-13 13:02:46
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 3
Words: 21,193
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/137656
Author URL: https://archiveofourown.org/users/Tierfal/pseuds/Tierfal
Summary: <blockquote class="userstuff">
              <p>The Master breaks things in the TARDIS until the Doctor almost goes insane, then they end up in the Vivarium, and <i>then</i> all hell breaks loose.  The Doctor is not liking any of this – and while he's at it, the dream-flashback-things really, really need to stop.</p>
            </blockquote>





	1. Part I

**Author's Note:**

> This little ditty was initially inspired by two very different but equally amazing fics – [Heart Heard Of, Ghost Guessed](http://www.whofic.com/viewstory.php?sid=35503&warning=Adult), and [Hard to Get](http://www.whofic.com/viewstory.php?sid=19886). It actually kind of started out as my brain's way of reconciling them, and then, last May, it grew a plot and took off and refused to let me work on anything else until it was finished, so here we are. XD I also have to credit [allchanges](http://www.youtube.com/user/allchanges)'s vid [Vom Selben Stern](http://www.youtube.com/watch?v=QZ_5XkatFWQ) (subtitled in English) for talking me into this ship in the first place, and (of course!) Eltea for doing the rest. :D If I had two hearts, I would give them both to her – this fic's beta-reader, cheerleader, and good-idea-suggester, not to mention the Theta to my Koschei for ten years now. (…and not in the cutesy-fangirl way; in the "Shit, I'm going to grow up to be a mass-murdering psycho" way.) <3
> 
> Warnings: language, snark, mild violence, sexual situations, spoilers through DW S4

“You’re a pathetic caretaker,” the Master announced. “I’m wasting away.”

“You could stand to waste a little faster,” the Doctor said without looking up. The TARDIS had ruptured a pipe and started spewing thick steam up through the floor, presumably in response to the nasty things the Master had been saying about her hospitality earlier, so he’d pried up a grate and was halfway into her entrails, attempting to repair the damage and soothe her pride. “You could also hand me the tape.”

He heard the Master pick it up—or pick up something from the multigalaxial mess that was the toolbox—but it didn’t make it to the Doctor’s hand. Instead, the Master flopped down on the grating next to him, dangerously close to his unprotected lower half. He glanced up, settling a reassuring palm on the TARDIS’s heated circuitry, but the Master was just lying there, his arms at his sides, at least for now.

“We were good, once,” the other Time Lord said. “When things were simple, and we were as simple as we’d ever be.”

The Doctor gingerly redirected a sparking wire, thinking it best not to encourage him.

“Back when we respected alien races for their culture, not their war machines. Back before either of us had committed genocide.”

“We were children,” the Doctor cut in, “and we’re not children now. Hand me the tape. It’s black and shiny and clearly tape-like; you can’t miss it.”

The Master heaved a deep sigh and folded his hands behind his head. “You remember,” he said. “You remember everything, no matter what you say. It’s the only thing about you that I never hate.”

The Doctor capitulated and hauled himself up out of the gap in the grating, brushing dust and particles off his front. He sat up fully and looked down at his ward-nightmare, who was lounging on the floor as if it could be remotely comfortable.

“You never hate my hair,” he remarked, getting to his feet and going to hunt for that damned tape.

The Master thought it over in detail, slinging one leg over the other at the knee.

“I hated it last time,” was the verdict.

“You didn’t meet me last time.”

“I saw pictures. It was awful.”

“It wasn’t awful; there just wasn’t much of it.”

The tape seemed to have evaporated. The Doctor wondered if the TARDIS had devoured it to spite him for keeping the Master around at all.

“It was disappointing,” the Master amended.

“What the hell have you done with the tape?” the Doctor asked.

There was a _kcck_ -ing sound as the Master spread his arms, a black ribbon bowing between them.

“It’s a metaphor,” he said. “Some kind of excellent poetry about the things that bind the universe, and how they’re dark and a little shiny and very sticky, and when they stick to themselves, they make a giant knot—”

The Doctor snatched the tape out of his hands and swung down to attend to the pipe again. If he could seal the breakage well enough and then assuage the TARDIS’s bruised ego, she’d heal back up in due time.

“I would have thought you’d appreciate universe metaphors,” the Master said, swinging his arms up and down to make grate angels.

“I would have thought you’d have learned to shut up in nine centuries,” the Doctor muttered back.

“That’s a talent one has to be born with,” the Master informed him, “the first time.”

The first time didn’t mean much when you piled enough years on top of it.

The Doctor stroked the patched-up pipe with one fingertip, gently caressing its mended curve, and then heaved himself out of the hole again. The Master lay as if sunning himself, as if soaking in the TARDIS’s energy, like a cat atop a radiator.

“You’re not much for shutting up either,” the Master said. “You like to hear yourself talk, mostly just because you’re the only one who talks that way.”

With the turquoise light of the TARDIS casting shadows on his face, he looked like a child telling scary stories with a torch held underneath his chin.

And that was part of it; a lot of it; the Doctor been wrong before, or he’d been too absolute—they were ancient and venerable and refined, but they were children all the same. They acted like children, for all their power, and that was a disaster in motion. The Master simply took the things he wanted, and when he had everything he’d been after, he started grabbing other people’s things instead. He didn’t want planets, or populations, or anything until the Doctor did—he didn’t care about his toys until someone else showed interest. He hated listening; he loved games; he prodded at the ribs just to pass the time. He was petulant and excitable and prone to changing moods.

They both were.

The Doctor didn’t have much of a track record for maturity, though he liked to think the Master made him look a little better in comparison. But the similarity was there, was inescapable, was seething in their quick-beat, racing blood. They were cut from the same cloth, carved from the same block of stone, and the whole TARDIS hummed at having four hearts in her core.

The Doctor gathered himself to his feet, the soles of his trainers squealing on the grate just enough to make the Master cringe. He went to the console and laid his fingers over the keyboard, trying to let the warmth of the TARDIS reassure him, trying to feel like everything he’d known and been for eras hadn’t changed.

“Why are you so angry at me?” the Master asked.

The Doctor jammed a finger down on a button, and a readout of the ship’s functions scrolled across the screen. He scoured them for another breakage or another leak. “Might have something to do with the fact that you killed six hundred million innocent people and left the rest to die.”

The Master yawned. “Most of them probably weren’t as innocent as they’d have you believe,” he pointed out. “Besides, you brought them all back. We’re like a yo-yo. That’s another good universe metaph—”

“And yet you _still_ managed to kill a dozen people in Downing Street and the President of the United States,” the Doctor cut in, chewing on his lip as he skipped to the next page. They still weren’t quite optimizing the flow of energy into her heart. Maybe there was a clog somewhere; he’d have to divert power along a few different detour routes and see which were efficient and which weren’t.

“They were politicians,” the Master sighed. When the Doctor glanced at him, he was still lying on the floor, though now he appeared to be trying to improvise a yo-yo from the tape. If anyone could do it, the Master could. “No one will miss them. People are always wishing politicians would drop dead anyway, _especially_ American presidents. I’m practically their fairy godmother for that.”

The Doctor pinched the bridge of his nose. “That mental image will give me nightmares for at least a hundred years.”

“Good job I’ll be here to cuddle you when you wake up screaming.”

“There will be no cuddling from you or anyone, or you’ll find my screwdriver in an unpleasant place.”

“Is that a promise?” the Master asked.

The Doctor glared in response to his grin and focused on the readouts.

—

The Master had somehow made the faucet twist its neck around like something out of “Poltergeist,” and it was currently spraying cold water everywhere. The Doctor was battling both a temperamental sonic screwdriver and the very wet, very curious fellow Time Lord at his elbow.

“Harold Saxon,” the Master said, apparently apropos of nothing.

“Never existed,” the Doctor muttered, because if you didn’t humor him, he humored himself.

“But it’s a good, strong name, isn’t it?” the Master went on. The Doctor fiddled with the electron concentration setting, and the sink made a gurgling noise but didn’t relent. “That was fun. I liked Harold Saxon.”

“I liked Professor Yana,” the Doctor said. He was going to go for a wrench in a minute.

“You would,” the Master said.

Midway through wondering if he had a sonic wrench somewhere, the Doctor paused.

“Explain something to me,” he said.

The Master patted his arm. “Well, Doctor, when a man loves a woman—”

“If you’re so bloody brilliant,” the Doctor interrupted, “which you _are_ , why do you keep breaking things?”

“I don’t break things.” The Master pouted, exaggeratedly. “Things break, and I happen to be in the room, or on the planet, or near them with a weapon, and you blame me, and I cry myself to sleep at night, unable to bear the stain of your ill will.”

The Doctor stopped without having mended the demonic plumbing. “Explain something else to me,” he said.

The Master attempted to flatten his extremely wet tie, looking at himself in the extremely wet mirror. “Much as I appreciate your acknowledgment of my superior intelligence, this explanation thing is getting a bit tedious.”

“Professor Yana,” the Doctor said. “He was kind, and brilliant, and completely selfless. He dedicated his life to the last chance, and he was going to die in his workshop so that the rocket could fly—to save everyone.” The Doctor had been kneeling on the linoleum in an ever-growing puddle, but now he forsook the incorrigible pipes and stood, watching the only other Time Lord alive. The Master looked back at him, eyes unrevealing. “But that was the Chameleon Arch. It can’t build a new person; it has to appropriate elements that were already there. Professor Yana is in you. Everything he did, you’re capable of.”

The Master met his gaze, unwavering, unmoved. “I’m capable of a lot of things,” he said. “As are you.”

The Doctor could hear himself breathing, could hear his pulses stuttering in his ears as both hearts skittered faster. They were like two glaciers now, built from a common source, frozen into behemoths. But they were shifting; they were always shifting, incrementally, and now that they had collided, perhaps they would meld. Perhaps they could cast off the topography, forget the ideological chasm between them, put aside the too-human standards for _good_ and _evil_ and focus in on a commonality that the universe had narrowed to just they two.

The faucet made a hideous noise and splattered water all over the Master’s face.

“Apparently,” he said, “fixing a sink is not among those things.”

The Doctor didn’t deign to reply as he settled in his puddle and fiddled with the screwdriver’s settings some more.

—

The Doctor was running out of things to repair. The Master’s talent for apparently inadvertent destruction of light fixtures, electronic devices, and anything that remotely resembled glass had settled to an average of about one broken thing every fourteen hours, and even the most complex fixes only took half that time. Relatively soon, the Doctor was going to have to find something else for them to do.

He was beginning to remember why domesticity had never agreed with him, which of course was a thought that wormed its way around the roots of the problem he’d shouldered now.

As a result of all of this sedentary behavior, he’d also been sleeping for considerable stretches. The pitfalls were numerous: first and foremost, any activity that left the Master unsupervised was extremely unwise; second, nowadays, the Doctor actually had time to dream. His dreams tended to develop alternate universes—to pursue _what-if_ s to their conclusions—and some of them were utopian, but most were not.

It was a nightmare that he had woken from today (“today” being relative, of course, because they were in the Vortex, which did not technically have a today, or a yesterday, or a tomorrow, but an indiscriminate “now”), and he was trying to shake it as he wandered down one of the halls, heading for one of the kitchens. He was hoping the TARDIS might see fit to supply him with some cake, and even if she still resented him for accidentally dropping the pressurized hammer into her workings when the Master had startled him approximately-yesterday, he knew she wouldn’t begrudge him dough to make biscuits. She cared for him too much to deny him comfort entirely. That was one of the things that made the trials worth it; that made things all right—he always had this place to come back to. He always had a haven that actively worked towards his happin—

A ceiling panel plummeted and smashed on the floor right before him, and he jumped half a meter and looked up just in time to see the Master’s cheerful face appear in the gap.

“What in the _hell_ are you doing?” the Doctor demanded, hastily revising his previous conclusions about the improbability of simultaneous bicardiac arrest.

“What does it look like I’m doing?” the Master asked, glancing about himself interestedly.

“Climbing around in the ventilation, you _lunat_ —”

“That’s exactly it,” the Master said. “Really, Doctor, you overanalyze everything.”

The Doctor gave him one last Oncoming Storm look and continued down the hall, pretending he didn’t tense just a little as he passed beneath the Master, who probably wouldn’t be above dropping eggs on his head.

But there were no projectiles yet, so he made it to the kitchen unscathed and began sorting out ingredients. He had a strange urge to put a mess into the oven and watch the right combination of time and heat turn it into something wonderful.

Sentimentality, he thought, had always been a weakness; so had the infuriating creature who broke through one of the panels of the kitchen’s ceiling four minutes later.

The Master clambered down onto one of the countertops, brushing plaster off of the old, wrinkled Oxford shirt he’d been wearing since they started out, and considered the Doctor, who might or might not have had a bit of flour on his nose.

“You know,” the Master said, “this is what you could have had. Way back. The first time.”

The problem was that you didn’t know better until the second time, and by then it was too late.

The Doctor busied himself with the sugar. “This time is the one we’ve got.”

He heard the Master sit down at the table and start tapping out his damnable drumbeat, presumably watching everything the Doctor did, waiting for him to turn around. The Master had always enjoyed forcing him to think about things he would rather have pushed away—which he called pragmatism, and which the Doctor called psychological sadism.

But the thing about regeneration was that it didn’t retroactively change your recollections. You had the leftover memories of another man, and you felt them as he had felt them; understood them as he had done. When the Doctor revisited the days when he had been Theta Sigma, every memory revolved around the bright-eyed, dark-haired young Time Lord who would become the Master, and the blazing, uncomplicated love was overwhelming.

But they hadn’t had this the first time, as it had turned out. Theta had been the beginnings of the Doctor, had been the foundation of all his instincts—Theta had run. He had felt intuitively that any feeling that strong had to be a lie, a trick, a trap. A cage.

It was hard to say who should have been asking for forgiveness now. It was all raw again when Theta rose in him, when the stupid, innocent, enviable boy he’d been tumbled to the forefront of his consciousness. Running, the first time, had been like being flayed alive. But he’d done it. And he hadn’t gone back.

Two fingers tapped four times. “What are you thinking about?” the Master asked, mockingly, because even now they could read each other so easily that he already knew.

The Doctor found a wooden spoon and started stirring. “I’m making a list of planets where it would be acceptable to keep you on a leash.”

“Kinky,” the Master said, sounding like he approved.

The Doctor snuck a few chocolate chips and didn’t respond. He was fairly certain there were only two sane reactions to his circumstances, and those were chocolate binges and suicide.

—

 _“Kosch—”_

 _The walls of Koschei’s room were white, bright white, a white that clung to your eyelids when you closed them as he pushed you up against their hard blankness._

 _“What if your parents—”_

 _“Get back early? They won’t. They’ll have more wine than they intend, and then they’ll stay later than they meant to. It’s what always happens. Besides—” His cool hand crept up Theta’s thigh. “I thought you got off to danger.”_

 _A weak, high laugh bubbled out of him; Koschei’s mouth on his throat was too wet for coherency. “I—well, I mostly get off to_ you _—”_

 _He felt Koschei’s grin and scrabbled for the other boy’s dark hair, burying his hands in it, curling his fingers, holding tight. As he arched his back, his head slid against the wall, and he couldn’t help marveling at how smooth it was, how uniform; Koschei’s family was so high-class, and somehow that made it even better when they sprawled amongst the finery and rutted like a pair of animals—_

 _Koschei’s teeth grazed the place his pulse beat in his neck, and he could barely breathe. The other boy’s voice hummed with just the faintest hint of hypnotic suggestion—they’d agreed not to play with each other like that, because it wasn’t fair, but Theta knew that Koschei didn’t even do it on purpose most times; it happened on its own when he wanted something so badly that he forgot._

 _“Say it.”_

 _“Kosch—”_

 _“Say it.”_

 _“But I—”_

 _“Theta.”_

 _“I l… Ahh… I lo—”_

The TARDIS slammed into something, and the force of the collision upended the entire room, pitching the Doctor out of the bed and onto the carpet.

That settled it: the sleeping would have to stop.

He was on his feet and scrambling towards the console room before he’d properly completed the thought.

The moment he’d careened into sight of the console, he discovered the problem. The problem was the Master, who was peering at the monitor and drumming his fingertips on the tarnished console rim.

“Hullo,” the Master said idly. “I think it’s safe out there.”

“You crashed my TARDIS,” the Doctor said flatly.

“Did n—”

“You _crashed_ my _TARDIS_.”

“I did _not_ ,” the Master protested. “I called her a disobedient whore, and she crashed herself.”

The Doctor crossed to the console and started petting everything he could reach. It would take her a week to forgive him for this one.

“Where are we?” he asked, casting the Master a look that he hoped was more severe than resigned.

“I’m not sure,” the Master said, fiddling with a lever. “I was trying for a planet where you could keep me on a leash, but then this pathetic hunk of junk saw fit to sabotage m— _ow_!” He jerked his hand away from the spark of high-voltage electricity the TARDIS had spat at him.

“Don’t you dare kick her,” the Doctor warned as the Master tensed to do just that. “She’ll take us somewhere terrible.”

The Master dropped onto the jumpseat, all stained white shirt and momentous pout. “Can’t be any worse than staying cooped up in here.”

Still stroking the side of the console in a reassuring manner, the Doctor looked at the Master, and then he looked at the isomorphic deadlock seal he’d spent the entirety of their first day installing on the inside of the doors.

“Give me three hours,” he said.

The Master sighed exaggeratedly and stretched. “In case you haven’t noticed, we’ve got pretty much eternity.”

“I’d noticed,” the Doctor said, and swept out of the room.

—

Three hours and ten minutes. Meh.

He returned to the console room to find that the Master had finally succeeded in making a yo-yo out of the black tape. The Doctor raised his own creation for scrutiny.

The Master blinked.

“Handcuffs,” he said.

“Not just ‘handcuffs,’” the Doctor explained; “handcuffs with an isomorphic deadlock seal, like the door.”

The Master was eyeing them as if they were made of snakes instead of steel. “I never should have taught you that trick.”

“Nope,” the Doctor said, flashing a grin.

Mutinously, the Master glared at the cuffs. “So they’ll only open for you. What happens if you die?”

The Doctor shrugged. “They’ll inject aspirin directly into your bloodstream, and you’ll die, too. Can’t have you wandering the universe without me.”

The Master’s fascinating golden-brown eyes widened and then narrowed. “You would never. You never kill if you can avoid it. Besides, why in the world would you keep a supply of poison in your own TARDIS?”

“I travel with a lot of women,” the Doctor said.

There was a pause.

“Human women,” the Doctor went on. “Who have a tendency to turn into headachy, cramp-ridden harpies once a month.”

The Master smirked. “More harpyish than usual, you mean.”

The Doctor snorted, opening the cuffs and then shutting them with a satisfying _snap_. “You’re just bitter that Martha tricked you.”

“You’re the one that called her a harpy,” the Master said.

“I wasn’t calling _her_ a harpy,” the Doctor told him. “I was making a humorous generalization. I shouldn’t have expected you to follow the logic.”

“Clearly, you shouldn’t have,” the Master said.

There was a pause, and then the Master nodded to the shackles in the Doctor’s hands.

“Those are the only way I’m getting out of this ship, aren’t they?” he asked.

Wordlessly, the Doctor nodded, and the Master sighed and held out his right wrist.

“This is just getting kinkier by the minute,” he said as the Doctor locked them both in. “Do you have whipped cream?”

“No,” the Doctor said, “but I’m going to get a gag next time.”

—

The Doctor stepped out cautiously, tugging the Master behind him. “Where exactly did you crash us?” he asked.

“No idea,” the Master said. “I was trying to figure it out, but your miserable ship wouldn’t tell me a damn th— _ow_!”

The door had hit him on his way out. The Doctor had been waiting _nine hundred years_ for that to happen.

“Don’t laugh!” the Master reprimanded, rubbing gingerly at his backside and giving the TARDIS a rather impressive death glare. “This is entirely your fault.”

“No,” the Doctor said, “it’s your fault, for being an unbelievably slow learner. Come on, take a guess—when and where do you think we are?”

“Do you always treat mastery of time and space like a game show?” the Master muttered, but he gave in and started to look around.

They were in a garden, by the looks of things—no, that wasn’t right; it was dense, lush greenery, too thick and tangled to be cultivated. They were in a jungle if they were anywhere, except…

The Doctor tilted his head back.

“Probably a protected rainforest of some kind,” the Master was remarking, examining the nearest vine. “Well-protected; things are growing extraordinarily well.” He kicked at the rich soil with one scuffed dress shoe, and then he jumped experimentally. “Stop the presses,” he said, interested now. “This is definitely a preserve; there’s metal under there. Knew it was too good to be—what _are_ you staring at? I’m not massaging your neck later, I’ll tell you that.”

The Doctor pointed.

The Master glanced cursorily upward, making a face. “Did you leave your bird-watching guide in that pathetic pile of insubordination that you call a ship? Would you like me to fetch it f…” He paused, and then he looked up again. This time, he noticed that the sky was white.

Well. The “sky” was white—because it was actually a dome arching high above them, dotted with sun-simulating lights.

“We’re in a terrarium,” the Master concluded flatly. “Brilliant. I can cross that off my bucket list. Let’s go to New Vegas. No one will even care about the handcuffs there. We can play the same slot machine, and I’ll pretend to get drunk. It’ll be romantic.”

The Doctor took out his screwdriver and found the echolocation function. The south wall was the closest, so he swiveled on his heel and started towards it, dragging a reluctant Master behind him.

“Can’t we take the TARDIS? It could be miles.”

“Don’t whine. I don’t want us to land a spaceship on top of some endangered animal they’re trying to breed. We’re disturbing the ecosystem enough as it is.”

“You disturb me all the time, and no one cares.”

“That’s because you’re obnoxious.”

“So are people who stick bloody terrariums out where TARDISes with their own agendas are going to land.”

“It’s your own fault for speaking to her that way.”

“She’s a bloody _ship_!”

“You could stop using that word.”

“Bloody, bloody, bloody, you bloody fucking martyr—”

The Doctor rounded on him sharply. “If you’re going to be childish, I’m going to make a cell for you, deep in the TARDIS, and I’m going to seal it shut. We’ve got eternity, and you can spend it alone if you like.”

Their eyes met, and held, and the Master glared at his captor for a long, long moment before he dropped his challenging gaze.

“Right,” the Doctor said, more gently, and moved off again, pulling the Master along.

It wasn’t too far to the end of the enclosure, though it felt like longer than it was with the Master deliberately ignoring every single exotic tree or flower the Doctor pointed out.

The wall, when they reached it, was made of elegant steel, curving up over their heads—definitely a dome, then. Before the Master could make a sardonic comment about fruitlessness in a garden—yes, they knew each other far too well—the Doctor spotted a place where the steel transitioned smoothly into glass, presumably to make an observation window of some kind. Sure enough, as he hauled the Master through the last of the undergrowth, he saw that what looked to be an expansive command center lay on the other side. It boasted various panels dotted with all kinds of screens, lights, dials, and buttons, and the Doctor glimpsed a hallway in the back leading elsewhere. He also had an excellent view of a man dressed in a navy-blue boilersuit, who was dozing in the rolling chair in front of the broadest console.

Making a mental note to ensure that the Master didn’t immediately try to press all the buttons at once, the Doctor knocked demurely on the glass.

The man started awake, his head snapping up, and revealed himself to be humanoid, blond, and relatively young. He gaped at his pair of visitors in disbelief.

The Doctor attempted at a winsome smile.

The young man stood uncertainly and approached the glass, so the Doctor leaned in towards him.

“Hello,” he attempted, raising his voice in the hopes of being heard. “Can you tell me where we are?”

To the Master’s distaste, the young man swallowed and stared a bit more before he mustered his voice.

“How—how did you get in there?”

“Magic,” the Master muttered.

“Hush,” the Doctor told him. “We’re… a bit lost. More than a bit lost. Is there a way for us to get _out_ , by any chance?”

The man stared at them just a little longer before he nodded uncertainly.

“There’s a maintenance entrance just… here, hang on.”

He disappeared past the edge of the glass, and the Doctor took the opportunity to get a good look at himself and his companion. He looked about the same as always, if perhaps a bit more harried, with a few grease smudges on his hands from putting the finishing touches on the isomorphic lock, and he was handcuffed to a man with a dour expression and a pair of mesmerizing tawny eyes. The Master had long since given up on his suit jacket and his tie, and the Doctor thought he could detect a few ice cream stains down the front of his untucked shirt, but there was still something strangely commanding about him. That had always been one of the Master’s many talents.

A hairline crack appeared in the steel wall, at first just a horizontal line of light a little ways above their heads, but it resolved itself into the approximate shape of a door, and then it swung open. The young man from the control room was beckoning nervously.

“I’m not sure how tight the airlock is,” he told them. “Can you hurry?”

Without further ado, the Doctor complied, dragging the Master into the newly-revealed corridor after him. The young operator pushed a large red button on the wall, and the door sealed behind them again.

“Now then,” he said, not entirely steadily, looking between the two of them. “Who exactly _are_ you?”

“Oh,” the Doctor said, “we’re supposed to be here. We’re authorized. We’re extremely authorized. We’re…” He fought the psychic paper out of his pocket and flashed it at the bewildered young man, who only got more bewildered as he squinted at the imprint.

Then he went from squinting back to staring, his eyes wide and impressed.

“ _Oh_ ,” he said. “Oh, I’m terribly sorry. You’re a bit early, but—well. The equipment’s all here; please make yourselves at home. I’ll just—I’ll fetch the Director, and he’ll be with you in a moment. Please press the call button if you need anything. I’ll be on my way, then—”

With an anxious ingratiating smile, he turned and fled down the hallway the Doctor had seen before.

The Doctor flipped the paper to look at it.

“Apparently we’re health inspectors with the absolute highest clearance from the government of… Poltiro? I’ve always wanted to go to Poltiro! D’you know what that means? That means—” He pulled them into the control room and gazed past the glass, appreciating it this time. “That means we’re in the Vivarium. _Brilliant_. It’s this project they’ve got, where they started out trying to replicate the earliest planetary conditions, just a big wash of organic compounds, and have been trying to accelerate its growth to see how their world must’ve been born. We must be well into it by now, if they’ve got insects; pity we tromped all over it, b—”

The Master sat down on the rolling chair and tried to fold his arms, leaving the Doctor extremely unbalanced as he pulled back.

“Have you heard that psychic paper is outlawed on J’keem?” the Master asked. “They made an official statute after that time we posed as an embassy from Yvraïl Three.”

“That wasn’t my fault,” the Doctor reminded him, sounding slightly more plaintive than he would have liked. “We couldn’t exactly tell them we were Time Lords cutting class because you’d just got your TARDIS.”

The Master smirked a little. “It was fine until you immediately struck up diplomatic conversation with the king.”

“They were turning away refugees by the thousands!” the Doctor protested. “I had to say something.”

“And then he started _listening_ to you.”

“You’re just angry because I doodled all through Galactic Rhetoric, and you got top marks.”

“Which is how it went with _every_ class, you miserable underachiever.”

They shared a long, goofy grin before they remembered that they were supposed to be bickering.

The Master cleared his throat. “If you see a Self-Destruct button,” he said, “do let me know.”

“They’d never make it that easy to destroy the Vivarium,” the Doctor informed him. “Billions of investors, thousands of scientists, and, by this point…” He ran his teeth over his tongue, slipping his glasses on to study the engraved plaque on the console. “This can’t be right. What date does that screen show?”

The Master drummed his fingers on the console. “Saturday, November twenty-first, four-thousand and four. And it’s a quarter after six in the morning; the Director’s going to come in his jammies.”

“You’d be surprised how many directors I’ve met in their jammies.”

“No, I wouldn’t.”

The Doctor decided not to respond to that, focusing instead on the readings that scrolled across the nearest screen. “This is bizarre. It looks like everything’s in normal order, but they can’t possibly have promoted so much advancement in just a few hundred years…” He reached for the screwdriver, expecting that perhaps the real results were encrypted, only to receive a strong jerk on the handcuffs as the Master tried to spin himself in the chair. The Doctor gave him a dirty look—and then saw that the Master was watching a tall, broad-shouldered man in a nice suit stride down the hallway towards them. He pocketed the screwdriver again, slightly hastily, and flashed a smile, trying to look reputable.

The Director appeared to have come alone, though he was intimidating enough without backup. Offering a thin but inoffensive smile in response to the Doctor’s, he held out a hand to shake and then noticed the cuff preventing the Doctor from reciprocating straightaway.

“Is this some kind of… prisoner and convict arrangement?” he managed to ask.

“Yes,” the Master said, at the same moment the Doctor answered, “No!”

There was a brief silence, during which the Doctor determined that they had made a slightly unfavorable first impression, if the Director’s skeptical eyebrows were anything to go by.

Now that the Doctor thought about it, the rest of the man’s features were rather skeptical, too.

Sighing inwardly, the Doctor produced the psychic paper, which assuaged the skepticism at least for now.

“Ah,” the Director said, and apparently his eyebrows were just generally expressive, because they arced like dark parentheses. “I’ll give you the full tour, then, Mr. Smith, Mr. Saxon.”

The Master gave the Doctor a smug look, as if feeding suggestions into someone else’s psychic energy and solidifying a “good, strong name” was something to be proud of.

The Doctor frowned back and assumed he would get the message, because he would.

All fine suit and huge frame, the Director led them down a series of halls and thence out to a labyrinthine network of desks and cubicles, in and at which dozens of men and women leaned over telephones and computer screens, the low, humming harmony of progress all about them.

“This is primarily our fundraising branch,” the Director explained, sweeping one capacious hand. “You’re welcome to conduct interviews as you like; I’ll also introduce you to our head of human resources.”

“You’re charmingly transparent,” the Master declared. “In fact, I can’t imagine why anyone would waste his time poking around and irritating your extremely efficient employees. Smith, old chum, what exactly are we looking for?”

“Your manners,” the Doctor said. “Oh, I’m sorry; those are a myth.”

The Master grinned, and the Director cracked a thin smile.

“Right,” the Doctor said, suppressing a bit of a shiver at the juxtaposed titles. “I’m afraid that we’ll need a list of all your investors and an index of their contributions, preferably with your signature at the top. Formalities, you understand.”

“Of course,” the Director said. “Why don’t we stop by my office, and I’ll get you a ground plan and turn you loose?”

“Smith likes that part best,” the Master said contentedly, and the Doctor couldn’t argue with that.

—

The Doctor handed the Master their map and put his uncuffed hand in his pocket, toying with the screwdriver. “If you see any doors that say ‘Restricted’ or ‘Authorized Personnel Only,’ give me a yell.”

“For such a smarmy, uptight goody-two-shoes,” the Master remarked, “you seem to enjoy completely abandoning even the slightest pretense of abiding by the rules.”

“It’s for a greater cause,” the Doctor said.

“So illegal activity is acceptable on a small scale?” the Master inquired as the Doctor spotted an information panel on the wall and led them over to it, touching the screen to clear the default logo and considering the buttons. “That’s a slippery slope, Doctor. Where exactly do you draw the line? I know you’ve killed deliberately; I’ve kept track of the recent ones. So what’s the distinction? Your enemies die, and everybody else has your protection? Your opinion decides the fate of every living being? That sounds an awful lot like what I was doing from a different point of view.”

“You’re oversimplifying,” the Doctor said, taking out the screwdriver and applying it to the screen. “No, not even that—you’re overcomplicating. I don’t pick out who lives and dies. I try to save as many people as possible, and there are casualties. That’s all. Oh, hello.”

The screwdriver, of course, had done the trick—he’d slipped into the mainframe computer and brought up the list of investors. Another sonic setting and a tap of a button brought all of the detailed information about the businesses scrolling across the display.

Or, rather, the suspiciously vague information about them.

“That’s a front company,” the Doctor mused. “And that. And that. Question is, what are they actually doing?”

“Not protecting themselves, for one thing,” the Master said. “Who puts all the secret things _in the computer_? What do they think a pen’s for?”

“Is that how you did it?” the Doctor asked idly. “Took over the world by writing stuff out longhand? So if these aren’t really biological labs and universities, what are they paying for?”

“Do you usually save the universe by asking rhetorical questions of whoever’s in earshot?”

The Doctor gave him a black look. “Yes. I usually do.”

The Master looked back, wide-eyed and blinking. “Well, Doctor, I haven’t any idea. It can’t possibly be that you’re reaching to start with, because you like to meddle in important events on purpose.”

Judiciously, the Doctor elected to ignore him. “Obviously there’s a purpose here beyond ordinary research. We’ll have to see if we can dig up some background on these companies when we’re not in the middle of the building… speaking of which, we should talk to the scientists. Where are the laboratories?”

“Over the river and through the woods,” the Master said. “I’m not a global positioning system.”

“You’re useless,” the Doctor responded, snatching the map away. “They’re extremely close; are you being deliberately contrary, or are you incapable of interpreting simple cartography?”

“Yes,” the Master said.

The Doctor rolled his eyes and led the way to the lab wing, where he headed unhesitatingly through the door that read _Development_.

This was a proper laboratory, all long metal tables, microscopes, centrifuges, and test tubes. The Doctor felt a little geekier just walking in, and he couldn’t resist the urge to slip his glasses on. He pretended not to hear the Master snort in the process of choking back a laugh.

A few of the scientists glanced up from their work, and a very pretty Asian woman wearing a lab coat stepped forward to meet them.

“Can I help you?”

“I hope so,” the Doctor told her, smiling brightly. “John Smith, health inspector. We’ve just got a few questions for you, if you’d be so kind.”

“For instance,” the Master purred, “do you have a boyfriend, and how committed are you to h—”

“The health agency is implementing a new partnership program,” the Doctor said. “One inspector who respects social conventions, one who doesn’t. Brilliant, isn’t it? Like ‘good cop, bad cop,’ except traumatizing and… well. Anyway, can I get your name?”

“And your phone number, and your home address?” the Master asked cheerfully.

The woman smiled, and the Doctor realized that the Master was probably employing his famous talent for hypnotic suggestion once again. The Doctor entertained the idea of deliberately infecting his traveling companion with Av’klarian strep throat and giving him a dry-erase board for communication.

On second thought, the Master with a dry-erase board sounded like a whole new category of horror.

“Kate Lee,” the scientist was saying. “As for the rest, you look like you’re already pretty occupied.” She nodded to the handcuffs, in the process of which she seemed to notice them more specifically than she had. “Where did you _get_ those?” she asked, kneeling, before the Doctor could direct her attention elsewhere. “They’re amazing! How—”

“Government issue,” the Doctor interjected. “Partnership program. It’s really quite something. So tell me, Kate Lee, how long have you been working here for the Vivarium?”

“Coming up on three months,” Kate said, straightening with a slightly sheepish smile. “All of us are pretty new—the Vivarium has been very proactive about hiring young researchers, which is great for the economy.” She grinned. “Not to mention great for us. It’s a good job—intellectually stimulating, but not too demanding. Decent hours, too, and the supervisors are always very specific about what they want us working on.”

“What are you working on?” the Doctor asked. That was always the million-dollar question, wasn’t it?

“We do a lot of chemical research,” Kate told him, gesturing to one of the scientists bearing a micropipet over a petri dish. “At the moment, our larger task is to develop a compound that maximizes biological growth—and to concentrate it in an airborne form.”

“Airborne?” the Doctor prompted. “What, so that you can just channel it into the Vivarium, and everything grows at once?”

“We’re hoping it’ll speed up all the natural cycles,” Kate confirmed. “Everything dies faster, reproduces faster, evolves faster. Then we learn more. It’s hard to appreciate what you’re seeing when there are only a few life cycles in your own lifetime. If we can show people evolution in action, they’re going to have twice as much faith in the project.”

“Right,” the Doctor said. “Investors are skeptics.”

“Especially the ones that conceal their identities,” the Master put in, beaming when the Doctor sent him another dark look.

“Do they?” Kate asked. “I guess I can understand that—it’s a risky business venture, and not every company would want their involvement to be publicly known.”

“Fair enough,” the Doctor said. “So, Kate—you’re making aerosol life steroids—”

Kate grinned. “If you want to call it that.”

“More fun. That’s a lot to have accomplished in three months, isn’t it? Mind if I ask what your predecessors were working on?”

“We only got their data,” Kate told him. “We sort of inherited it from management when we came in. They’d made a water-based stimulant—fire up the enzymes, funnel in nutrients. We’ve actually adapted a lot of it for our version.”

“Why reinvent the wheel?” the Doctor agreed. “I think all that’s left to ask is… have you any idea where your predecessors _went_?”

Kate hesitated, and her smile was a bit more cautious this time. “I gather they’d sort of hit a wall,” she said. “Run out of ideas for how to take it further, you know.”

“And the higher-ups thought they’d bring in some new blood?” the Master asked sunnily.

Kate blinked. “Yeah,” she said slowly. “Something like that.”

“Right,” the Doctor said. “Great, then. Thanks very much, Kate Lee.”

“Water-based, airborne,” the Master mused, grinning. “What comes next?”

“I’m not sure,” Kate answered, smiling tentatively.

“I didn’t think so,” the Master replied.

“Oh, come _on_ ,” the Doctor said, hauling him back out to the hall, leaving a startled Kate Lee and her three-month-old lab team behind.

“You don’t have to intimidate people on purpose,” the Doctor muttered as they moved on down the corridor, looking for other doors of interest.

“But I’m good at it,” the Master protested. “And I miss the benefits of uncontested world dictatorship. You do realize that you _erased_ all of my hard-won accomplishments?”

“I gave you a blank slate,” the Doctor said, “instead of turning you in to the Judoon and leaving you to their mercy or lack thereof.”

“I should be thanking you on bended knee,” the Master remarked. “And doing your dishes, and rubbing your back, and buying you flowers—”

“What’s this?” the Doctor murmured, peeking into an open storeroom. “Look here, come on.”

“I’m attached to you; you don’t have to call me over. I’m not a dog.”

“Too bad,” the Doctor said. “You’d be right at home in this company.”

The right wall was composed entirely of stacked cages, their fronts lined with wire. Inside of the cages, chickens, pigs, and, in a few extremely large structures, small cows paced and stared out of their confines.

“What is this?” the Doctor asked again, drawing the screwdriver and scanning the strange menagerie. “Why would they…?”

“Maybe they need test subjects for their growth-hormone anthrax thing,” the Master suggested sardonically. “Maybe the employees prefer their food extremely fresh. Can we go? It smells terrible in here. Reminds me of Earth.”

“Lay off,” the Doctor snapped, finding another information screen and drawing up a list of inventory.

“You’re supposed to laugh,” the Master told him. “It’s Gallifreyan humor.”

“No, it’s just you.”

“ _Just_ me? It’s never _just_ me. I am monumental.”

“Your ego is. Why do they need two dozen chickens when they’re trying to replicate evolution in the first place?”

“You’re such a cynic, Doctor. You always assume it’s _foul play_.”

The Doctor stared at him.

“Foul play?” the Master repeated hopefully. “Foul, fowl… you’re getting slow in your old age.”

A little bit more of the Doctor’s soul died.

He heard a creak, and, turning, discovered another man in a boilersuit, this one middle-aged and pushing a trolley cart loaded up with buckets and boxes, all of them sealed.

“Hullo,” he said, pushing back his cap. “Can I help you?”

“John Smith, health inspector,” the Doctor volunteered, flashing the psychic paper.

“Harold Saxon, sex machine,” the Master added.

The worker’s eyebrows rose, but he didn’t comment. “Good to meet you. What can I do for you?”

“Tell me what they’re doing with the small farm you’ve got here, for starters,” the Doctor said.

The man rubbed at his forehead. “Couldn’t tell you that,” he said, which was about as much as the Doctor had expected. “Though I ought to tell you that it’s a quarter of six, and we’re about to shut down around here. I’m sure you can come back tomorrow.”

“Ah,” the Doctor said, exchanging a glance with the Master. “I suppose we will, then.”

It was one of the Doctor’s more anticlimactic exits, but there wasn’t much to be done for that.

“I refuse to break back in overnight,” the Master announced, more loudly than the Doctor would have liked, as they followed the signs towards the main doors. “If you try to make me, I’ll scream and alert all the night watchmen.”

“I’m sure there will be a decent hotel in the town,” the Doctor said as they stepped out into brisk air of the evening. “We can stay there tonight. Let me know if you see an automated teller machine.”

“You could just call it an ATM like everyone else.”

“I try to spell it out in the hopes that eventually people will stop adding the redundant ‘machine’ after the acronym.”

The Master pursed his lips. “The power of positive reinforcement never worked for me.”

“Noticed.”

“I favor the power of corporal punishment and demonstrative explosions.”

“Noticed that, too.”

“Look, an ATM machine!”

“You are disgusting.”


	2. Part II

**Notes for the Chapter:**

> I love pistachios. But they _are_ pretty evil.

“This is hell,” the Master said. “I’ve thought it all over and done the math, and this is definitely hell.”

The Doctor was attempting to jury-rig a multipurpose scanner out of their hotel room’s television remote, alarm clock, and smoke detector, with a few parts from the electric toothbrush he’d bought in the shop downstairs.

Yet another reason why every establishment really ought to have a shop.

“Are you sure it’s hell?” the Doctor asked bemusedly. He’d temporarily unlocked the handcuffs, because it was hard enough to focus through the commentary without fighting for control of his hand as well. “It could be Tartarus. Or Naraka. Or Xibalbá, depending on whom you’re talking to.”

“It’s hell,” the Master announced. “I’m investigating an oversized science fair project on a planet your PMSing TARDIS picked, I’m handcuffed to _you_ , and the only thing I can find to eat is pistachios.” He snapped another shell open and flung it into the bowl he’d balanced on his stomach. “ _Hell_.”

If the Doctor could magnify the capacity of the sensor from the smoke detector, since it already gauged temperature, particle concentration, and carbon monoxide levels— “Don’t you like pistachios?”

“I love pistachios,” the Master said. “Which is precisely why I _hate_ them, because they’re impossible to open. They exist solely to mock anyone who tries to eat them, and you think _I’m_ sadistic.” He wrestled with another one, his cheeks coloring. “ _Fuck_!”

The Doctor reached across the bed and subjected the stubborn pistachio to a quick jolt of sonic energy, which popped the shell cleanly in half, and then he returned to his work.

There was blessed silence for a moment, and then—

“You _bastard_ ,” the Master said.

“You’re welcome,” the Doctor said.

“Patronizing a prisoner is bad form even for you,” the Master muttered. “I’m willing to bet the Shadow Proclamation takes my side on this one. This fits squarely under ‘cruel and unusual punishment.’”

“You want to stop by and ask them about it when we’re done here?” the Doctor asked.

“No.” The Master was pouting again. “That woman creeps the living hell out of me. She looks like all of my librarian-related nightmares at once.”

“You were disruptive,” the Doctor reminded him. “The librarians had every right to try to intimidate you.”

“I wouldn’t have been disruptive if you hadn’t made me yell at you,” the Master fired back.

“You didn’t _yell_ ,” the Doctor said. “You _chased_ me through three halls of reference books, screaming like a maniac. G through P. I remember.”

“You deserved it.”

“You deserved the reprimand. And the nightmares.”

The Master snapped another pistachio open and threw half of the shell at the Doctor’s head.

The Doctor soldered one last connection with the screwdriver and then stood up, looking at the Master sternly. “All right. Bedtime.”

The Master beamed. “Are you going to tell me a story?”

The Doctor relegated the pistachios to the nightstand next to his scanner, securely replaced the handcuffs, and settled on the other side of the double bed. “Once upon a time,” he said, “there was a Time Lord who demonstrated such inconceivable immaturity that the wiser, handsomer Time Lord babysitting him had to abandon him on a planet entirely populated by librarians.”

“You would never,” the Master scoffed. “You don’t believe in suffering unless you’re the one doing it.”

The Doctor set his jaw and turned out the light.

It was quiet for a moment, and as his eyes adjusted—extremely quickly; humans had it bad—to the dim city lights that filtered through the blinds at the window, he dared to hope they might have achieved something like peace.

Then the Master shifted, and his dreams were crushed.

“Stop touching me,” the Doctor said.

“I’m not.”

“Yes, you are.”

“Well, maybe that’s because you _handcuffed us together_.”

“It was necessary. Is necessary.”

“That, or you just like bondage. Bet you learned it from the Freak.”

“His name is Jack.”

“Bet you learned it from Jack the Freak.”

“Jack Harkness.”

“Jack Harkness the Freak. My, but you’re hung up on specificity tonight. You should just be glad I didn’t call him the Fuckbuddy, since that’s obviously the reason you brought him alo—”

“If you don’t shut up this _instant_ and go to sleep, I will use the newest sonic setting to interfere with your gag reflex and leave you vomiting up pistachios all night. Do _not_ tempt me, my friend.”

There was a merciful silence.

“A sonic screwdriver can’t do that,” the Master decided.

There was another.

“…can it?”

“Go to sleep,” the Doctor said.

There was a third silence, presumably just to round things out.

“…you think we’re friends?” the Master asked.

The Doctor buried his face in the pillow.

—

 _Koschei’s bedroom had a balcony that looked out over the terraces, the field, and the forest. The last of the sunbeams struck sparks on silver leaves, like steel in a forge beneath the burnt peach-orange of the sky, but Theta was looking up at the first of the stars. Koschei’s long fingers were stroking through his hair, and the sky was darkening to rust around the little points of light._

 _Koschei’s hand drifted down to his shoulders, over his back, fingertips brushing at his spine. “Keep thinking that hard, you’ll hurt yourself.”_

 _“I’m not,” Theta said. “And I won’t.”_

 _“You’ll strain something,” Koschei said, smoothing his hand over Theta’s forehead, as if he might rub the wrinkles out. “I know you. And then you’ll whine.”_

 _Theta peeled his gaze off of the sky, smiling. “Then I guess you’ll just have to shut me up.”_

 _Koschei’s deep blue eyes looked violet in the failing light. “Good thing,” he murmured, leaning in, breath cool and moist in the dry night, “you’re so easy to distract.”_

 _Theta grinned into the kiss, spreading his fingers on Koschei’s neck, feeling his pulses, touching his ears. He was still grinning when Koschei curled one hand in his hair and the other around his wrist, dragging him back into the room, back to the neat bed, last night’s rumpled sheets spread and folded and hidden away._

 _“What’s the rush?” Theta asked coyly as Koschei pushed him down on the mattress, climbing over him, straddling his hips. “We’ve got eternity, you know.”_

 _Koschei pinned his wrists above his head, mouthing warmly at his jaw. “Eternity’s not long enough.”_

 _Theta writhed, back arching, stretching for Koschei’s warmth. “I’m not—I’m not thinking anymore—”_

 _Koschei drew his tongue slowly up Theta’s throat, and his soft breath sent waves and tremors through Theta’s very bones. “That’s the way I like y—”_

The Doctor woke up with a deep gasp already past his lips, tumbling back into the present only to see the Master hastily withdrawing one hand from beside his temple.

“What are you _doing_?” the Doctor yelped, loud enough for a flash of guilt on the behalf of their neighbors. His voice hardened. “You have _no_ right to read my dreams. None. That’s far out of bounds, even by your standards.”

“It’s the only way to know anything about you,” the Master retorted, flexing his fingers, his eyes gleaming in the dark. “Anything other than your firmly-held belief that technobabble is good for the soul, anyway.”

“It is good for the soul,” the Doctor said. He shifted away, facing the wall, trying to relax his shoulders and finding them implacable. “You should try it sometime, if you still have one.”

“Two hearts and no soul,” the Master said. “Imagine that. Sounds like typical Time Lord physiology to me.”

“Leave it,” the Doctor warned, rolling over again to look at him.

“Do you defend them, too?” the Master asked bitterly. “The _venerable_ Time Lords. Since you and I are the only ones who survived, logic would say we’re the strongest, don’t you think? That’s a laugh. They tried to turn us into soldiers… instead, they made you into an attention-deficit, depressive neurotic, and they turned me into a megalomaniacal psychopath.” He grinned, viciously. “I’d call that naught for two.”

The Doctor watched the flickering eyes. “Would you go back?” he asked.

The Master’s voice was flat. “We can’t. You said so yourself. You _caused_ it.”

“I know that,” the Doctor answered. “But if we could, would you?”

The Master looked at him, silently, and then he leaned in very close, his eyes alight.

“In a nanosecond,” he said.

Steadily, belying the way his insides curled, the Doctor met his gaze. “Why?”

The Master smiled crookedly. “Because it’s home.”

After a moment of stillness, the Doctor wriggled his fingers, adjusting the angle of his wrist in the handcuff, and nodded vaguely.

“What about you?” the Master purred. “Would you go back to Gallifrey?”

They knew each other far too well, which was why the Doctor knew that the truer question was _If we could do it all again, would you look at me instead of at the sky?_

“No,” the Doctor said, and turned his back on the last fellow survivor of his species.

The last fellow survivor of his species breathed warmly on the back of his neck, and he twisted away.

“Not even if we had my old bed again?” the Master asked.

“Go to _sleep_ ,” the Doctor said.

“I don’t like sleeping,” the Master muttered. “It’s too damned human.”

“So is whining incessantly about my rules.”

“You know humanity is contagious.”

“I hope so,” the Doctor said, and he pointedly shut his eyes and his mouth.

—

 _They were in their shared room at the Academy, in the bed made for one, sticky and sated, one of Koschei’s arms bent under the pillow, the other wrapped around Theta’s waist. They were just looking at each other, saying it all silently, because telepathy wasn’t quite as wonderful as knowing someone so well that you didn’t need it in the first place._

 _“Theta,” Koschei said after a long time, after full minutes had passed. “If you ever… if you ever think you’re getting tired of me, just—tell me so. I can change. I can be anything you want.”_

 _Theta was supposed to say “Don’t be ridiculous; I want you, Kosch, and that’s it.” That was what happened next; it was a given; except… he didn’t speak at all._

 _Koschei’s hand lifted and settled against his cheek, brushing his damp hair back, smoothing a thumb over his cheekbone._

 _“I promise,” Koschei said, and then he proved it._

 _He just sort of—faded at first, the colors of his skin and his eyes dulling, the contours of his face and his shoulder getting fuzzy, and then he blurred._

 _Slowly at first, and then more quickly, Koschei… changed. He had a long face with a dark beard and strangely sad eyes, and then his face was different, and he was smirking, but not too unkindly, and then his eyes flared yellow, the pupils narrowing to slits. Then they settled to an almost-familiar gold-flecked brown, and a warm grin spread across his face._

 _“I told you,” he murmured, lifting his right hand, a green ring gleaming, to brush the tips of his fingers over Theta’s cheek again._

 _“But you’re different,” Theta said, voice quavering. “I don’t want you to to be different. I don’t want you to disappear.”_

 _Not-Koschei smiled again, lopsidedly. “I’m not going anywhere. And I never will.”_

 _Hesitantly Theta laid his hand over this new man’s where it had settled against his jaw. He ran his thumb over its knuckles, over its breadth—_

 _“Who are you?” he asked._

 _Another smile. “That’s not as important as what I am.”_

 _Theta raised his other hand, pressing it against the man’s chest—right and left, two hearts._

 _“What are you, then?”_

 _“Yours,” the man whispered, the corner of his lips curling up._

—

Groggily, as he swam into consciousness, the Doctor tried to scrub both hands across his eyes only to encounter the handcuffs again.

Then he was awake.

So were the birds outside the window and an invasive beam of strong sunlight.

Well. Sunlight couldn’t really wake up, per se. Well, it couldn’t unless—

Anyway.

“What time is it?” the Doctor mumbled, glancing over at the Master, who was lounging on the bed, effectively acting as a dead weight on the handcuffs.

The Master fished in his trouser pocket and came up with a familiar fob watch, which he consulted calmly. “Nine-thirty, local time.”

“What?” The Doctor rubbed at his gritty eyes with the back of his free hand. He really needed to give up sleeping. Permanently. “How did it get that late? We should have been there hours ago; we could have explored without any interference.”

“I suppose that’s what happens when you dismantle the alarm clock,” the Master said mildly. “You should be glad there wasn’t a fire; we'd be dead.”

“You could have woken me,” the Doctor muttered, climbing out of the bed and hauling the Master behind him.

“But you’re adorable when you sleep,” the Master said, and the Doctor whirled to stare at him. The Master winked. “Besides,” he went on airily, “I’m flattered that you still dream of me.”

“Not all of our nightmares are about librarians,” the Doctor said, picking up the scanner and focusing on it so he didn’t have to look at the Master’s face. “I _told_ you not to listen in on my dreams. And how, pray tell, did you get past all the psychic barriers?” They were nothing terribly sophisticated, because he generally only required blocks built to foil a clever human, but they should at least have had an effect. The Master should have had a splitting headache or something by now.

Maybe the Master couldn’t distinguish headaches from the drums.

“A magician never tells,” the Master said. “Guess I just know you better than you know yourself.”

“Guess your ego always stays the same.”

The Master grinned. “One more thing you love about me.”

The Doctor pocketed his scanner, ran a cursory hand through his hair, and started for the door, dragging the Master with him.

—

“John Smith, health inspector.”

“Harold Saxon, undergarment inspector.”

“Will you _shut up_?”

The Master was enjoying this far too much. The Doctor jerked hard on the handcuffs as they turned a corner into a new hall.

“You know very well I’m incapable,” the Master remarked. “I have an underdeveloped whatsit. Amygdala?”

“I don’t think you know fear, no.”

“That’s not the one. Hypothalamus? I lack inhibitions.”

The Doctor drew them back into the room full of farm animals, scanning up and down. “You lack a lot of things.”

“Including your scientific curiosity,” the Master said. “I hope you know killing prisoners with boredom is also a flagrant violation of the Shadow Proclamation.”

“If you had an attention span,” the Doctor told him, “this wouldn’t be a problem. Speaking of which, how did you manage to hold Earth under your iron thumb for a year without one?”

“Superior delegation skills,” the Master answered calmly. “Even your scanner is bored.”

Unfortunately, it looked like he was right—there weren’t any extraordinary readings; the scanner was beeping quietly at regular intervals. These life forms were perfectly normal.

“Why did you even make that thing?” the Master asked.

“Hunch,” the Doctor said, and he turned in a slow circle, adjusting the little satellite on the top. “Hang on.” He wavered rightward, then leftward, then centered it—there was a faint but detectable increase in the tempo of readings when he angled it towards the north. “Right, then,” he said, making a distinct effort not to be smug. “Come on.”

The way the corridors wound and crossed, it was impossible to move in a straight line, which led to a merry round of the labyrinth game.

If the Master made _one_ more comment about the Doctor’s talent for picking dead ends, the Doctor was going to shove the scanner down his throat and navigate by listening to his chest.

Directing them northward again, noting a tiny shortening of the interval, the Doctor was halfway down the latest hall before he noticed that he recognized this one.

“We’re going towards the Vivarium,” he realized.

“Just imagine,” the Master gushed. “ _Life_ in the _Vivarium_. Next they’ll put milk in milkshakes.”

“I’ve had a milkshake witho—”

“You have to be the thickest genius I’ve ever met.”

Before the Doctor could shut him up, possibly with the scanner, there was a substantial commotion further down the hall, just outside of the control room. The Doctor tried to jog over, but the Master dragged his feet, so they did more of a stumble-stagger thing.

When at last they arrived, a man with long black hair was most of the way into an elaborate protective suit, which a woman and yesterday’s young man were sealing carefully.

“John Smith, health inspector,” the Doctor said quickly, “and this is Harold Saxon, intergalactic criminal. He’s mostly harmless. What’s going on here, what’s all this?”

“Just the daily inspection,” the blond young man answered, fitting a glove on snugly. “Troy has clearance if you’d like to see it.”

“I believe you,” the Doctor said. “And we’ve met—what’s your name?”

“Eliot, sir,” the young man answered with a smile.

“Everything is under control here, Mr. Smith,” Troy told them just before the woman jammed his helmet on. He touched a button with one gloved hand, and after a stutter of feedback, his voice came through a speaker at the helmet’s base. “Routine, if you’ll excuse me.”

“Of course,” the Doctor said.

And of course they followed as Troy strode down the rest of the hall into the control room, and of course the scanner skipped a beep.

Troy positioned himself in front of the door to the enclosure, and Eliot pressed another button on the suit, which brought a darkened radiation visor swishing down, obscuring Troy’s face. Eliot smacked the operating button on the wall, the door hissed obediently open, Troy stepped out onto the fertile soil, and Eliot closed the door again.

“Now what?” the Doctor asked.

“Now most of us get back to work,” the woman muttered, departing, presumably to do just that.

Eliot reprised his spot in the rolling chair and leaned forward to the largest screen. “I’m supposed to keep track of all the times,” he explained. “So we know how long he’s in there, and then I can make a note of any unusual observations… it’s pretty boring stuff, though you’re welcome to stay if you like.”

“Love to, thanks,” the Doctor said cheerily.

The Master heaved a massive sigh. “He took the _chair_.”

“He only has one heart,” the Doctor pointed out. “He needs it more. Suck it up.”

“You are the bane of my existence.” The Master started making faces at his reflection in the glass. “When do we get to the part where things explode?”

“You’ll have to excuse him,” the Doctor said to Eliot. “He was dropped on his head as a child. Repeatedly, because his parents were trying to kill him.”

“The Shadow Proclamation has three chapters on slandering prisoners,” the Master said.

Eliot was chuckling, which was rather impressive given that they were essentially talking nonsense. The Doctor wasn’t sure whether to find the amusement flattering or disturbing. It was safer, he reasoned, not to decide, so he returned his attention to the still, tranquil, jungle-forest panorama laid out before them.

The Master was still pouting, but that wasn’t what struck him as the silence—broken only by the occasional squeak of Eliot’s chair as its occupant considered a different screen—spread out around them, filling the space. Artificial sunlight blazed down, backlighting the motionless leaves, and the Master sucked on the inside of his cheek.

The Doctor rubbed at the back of his neck, where the hairs were prickling portentously. “Something’s wrong,” he said. “Something’s off.”

The Master rolled his eyes. “Apparently not your desperate need to compensate for real intellect by being enigmati—”

“It’s quiet,” Eliot said, blinking. “I—I mean, I’ve been feeling funny all morning, sitting here, and I just realized why. It’s gone quiet.”

“And that’s all wrong,” the Doctor agreed in a low voice. “Because we saw insects yesterday, and birds, and _life_ , and now it’s all _gone_.”

“The trees are fine,” the Master said, eyes narrowing as he stared out past the glass. “Wouldn’t think you’d be the type to discriminate against slightly less sentient life forms, Doctor. And your scanner must be broken, because it measures life, and it brought us here.”

“No,” the Doctor said, “it measures _abnormal_ vital signs. Should pick up alien life in particular, present company excepted.”

The Master rolled his eyes and drummed his fingers on the console. “Figures we’re not even alien enough for y—”

Troy stepped into view, appearing from the edge of the window, looming up against the glass. The distant white lights sent his shadow sprawling across the consoles, and he raised one hand to knock twice.

“All clear,” he said, voice tinny through the comm. “Let me in.”

Eliot scurried to hit the button that opened the airlock door, and Troy stumped inside. Eliot rapped the switch again, and the door slid shut.

“All clear, then,” Eliot remarked contentedly. “We were getting a little worried, seeing as how it’s so quiet all of a sudden.” He started back towards the nearest console and drew up his spreadsheet, chewing his lip as he input the date and time. “You all right, mate? You’re awfully quiet yourself.”

The Doctor looked at Troy, who was turning his head slowly, considering the company and then the consoles from behind the darkly-shaded visor of his helmet.

“There are four light sources in here,” the Master muttered.

“That’s lovely,” the Doctor replied, glancing back at Eliot, who was searching for the key he wanted. “I’m glad they built this place to your drums’ standards.”

“Count the shadows,” the Master said.

There were four light sources in the control room, and five shadows spread from Troy’s booted heels.

“Oh, no,” the Doctor heard himself breathe, his heartbeats starting to thunder in his ears. “Oh, no, no, no, no, _no_.”

The Master swallowed audibly. “I always assumed that was just a catchphrase.”

“Eliot,” the Doctor said deliberately, “run. Run _now_ and do not stop until you are as far away from here as you can get. Off the planet if you can, now _run_.”

The young man rose from his chair uncertainly. “But—”

“ _Now_!”

Eliot ran, and the Doctor thanked his lucky stars, of which there were a few.

Just not enough.

“Now listen to me,” the Doctor said to the microscopic creatures swarming in the suit. “Listen close, because if you can make his voice work, you can understand. Troy, if there is any of you left in there, still feeling, _please_ do everything you can to fight them. Don’t let them move, or you will not be their last victim, and you’re strong enough; I know you are. And to the _parasites_ that have taken Troy, I will find you a home, find you a world, feed you, help you, save you, if you just _stop now_.”

The helmet of the suit tilted, as if there was still a thinking head inside.

“St… stop?” it asked. “But we… are st… starving…”

The Master’s hand tightened on the Doctor’s arm so quickly that his fingers tingled.

“Look at the shadows,” he whispered.

The Doctor looked closely, and the fifth one was growing—lengthening, creeping across the floor, expanding from Troy’s feet like radiation from a sun.

It was getting awfully close.

“One last chance,” the Doctor said, raising his voice. “One last chance to give this up before—”

“Toodles,” the Master cut in, turning and running straight down the hall, the handcuffs dragging the Doctor after.

“What are you _doing_?” the Doctor howled, lurching after the Master, trying to ignore the roaring of his hearts in his ears as he heard Troy’s footsteps start up, slow but unmistakable.

“You and I both know he was already dead,” the Master said, jerking them around a corner. “And we were about to be. Now think of something.”

“ _You_ think of something!” the Doctor fired back, his trainers squealing on the linoleum as they rounded another turn.

“You’re the one with practical experience,” the Master said.

“Fine!” the Doctor snapped, running ahead and shoving through a thin steel door. He slammed it shut after them and took the screwdriver to the lock, watching through the small porthole as Troy’s deliberate steps brought him around the corner and into view.

They slumped against the wall for a moment, catching their breath, and the Doctor hauled the Master’s hand along with his in order to run his own through his hair.

“Right, then,” he said lightly. “You must remember that Academy lecture.”

“They told us how to recognize foreign species,” the Master reminded him. “They didn’t usually conclude with how to _kill_ them.”

“An enormous oversight,” the Doctor said.

“Evidently,” the Master replied.

They both laughed uneasily, and then the creatures inside Troy banged his fists against the door.

“Exactly how strong is a sonic lock?” the Master asked.

“Let’s not wait and see,” the Doctor answered, pulling them up and starting off again at a run.

The labyrinth game was even more fun when you were running at top speed, careening through the halls trying to avoid untimely death. The Master’s scuffed dress shoes skidded as the linked Time Lords swung around a particularly sharp turn, and then his feet slid out from under him, and they toppled to the floor together, the collision knocking the Doctor’s breath right out of his lungs.

“That’s it,” he wheezed, gathering himself up again. The Master did likewise, one hand over his left heart, the other at the small of his back. “We need to get you a pair of Cons.”

“I have millions of cons,” the Master panted. “Some executed, some planned, some just fondly envisioned. Where the hell are we?”

“No idea,” the Doctor said. “Come on.”

Another short sprint brought them through a set of double doors, which swung open and then kept swinging as the Doctor took in the room they’d burst into.

It was a claustrophobic room with white walls. In the center of the far one stood a steel door with a small, square window, and beside it, a familiar blond was sitting cross-legged on the floor, leaning back with his eyes closed.

“Eliot?” the Doctor said incredulously.

“Oh,” Eliot said, looking up at them morosely. “Hello. With what you were saying—with whatever got Troy—I thought—well, I figured—”

“Spit it out,” the Master said.

“I hit the button for emergency lockdown,” Eliot responded. He sighed deeply. “And it worked great; set the alarm off and evacuated the building, just like it’s supposed to. Except apparently lockdown includes a quarantine of the area where the alert was activated.”

“Meaning here,” the Doctor said.

Eliot nodded miserably.

“Well,” the Doctor said, crossing to the door, “we can’t have that, can we?” He retrieved the sonic screwdriver and twirled it a little. “Does your lockdown include deadlock seals?”

He pointed, and the screwdriver whirred.

Nothing happened.

“Apparently it does,” the Doctor managed, lowering his arm.

The Master snatched the screwdriver out of his hand, changed the setting, and applied it to the glass, which shattered on contact.

“ _Quarantine compromised_ ,” a polite, vaguely female voice announced.

“Compromise is the foundation of progress,” the Master said, and kicked in the door.

The Doctor was a little bit impressed.

But just a little.

He jerked them back from the now-open doorway and ignored the Master’s outraged look, gesturing to their rather more vulnerable human companion.

“Eliot, you go first,” he said. “Lead the way.”

Eliot scrambled up and bounded off ahead, and the Doctor silently celebrated humans who could actually react in universe-threatening danger. They seemed to be few and far between.

The Doctor stopped celebrating when another desperate run brought them to a storage room that didn’t appear to have an exit. It didn’t appear to have much of anything at all.

Barely had the Doctor raised an eyebrow at Eliot when the boy’s knees were shaking, and he delved both hands into his hair, with which the Doctor had to sympathize at least a bit.

“Let me guess,” the Master said dryly. “It’s your first week here, and you fell asleep during the training slideshow.”

Eliot stared at him, torn between the larger horror and this new disbelief. “How’d you know?”

The Master smiled pleasantly. “I killed a few who did that.”

“Will you shut up?” the Doctor snapped. “Besides, when time reversed, we saved them.”

“ _We_ did no such thing,” the Master retorted, “and I killed them _before_ the paradox. I had to test the screwdriver, you know.”

Speaking of screwdrivers, the Doctor took his back, slammed the door to this room shut, and locked it behind them, and then he started scanning for objects of interest.

The Master, of course, had little choice but to follow reluctantly. “What the hell do they intend to do with a Vivarium full of Vashta Nerada anyway?” he asked. “Win first place at the annual invisible fish competition?”

The Doctor spared him a glance. The Master’s eyes widened.

“You think they’re making an _army_?”

“At this juncture,” the Doctor said grimly, “yes.”

The Master seemed to be floored. “They’re growing an army of bloodthirsty, practically invisible air-piranhas. That’s _gorgeous_. Why didn’t I think of that?”

They’d reached the back wall, but the sonic frequency indicated that there was another room directly behind it. They were rather trapped.

“Well,” the Doctor said, “empirically speaking, your plan was the best I’ve seen, since it actually worked. No one ever gets to the takeover stage, but you made it well beyond.”

“Oh, Doctor,” the Master said, grinning. “I didn’t know you cared.”

The Doctor wrinkled his nose. “Yeah, well… anyway, speaking of bloodthirsty, practically invisible air-piranhas, let’s make sure the whole of the universe doesn’t get eaten by them.”

“To hell with the universe,” the Master said. “Let’s make sure _we_ don’t get eaten.”

“Who are you?” Eliot asked uncertainly. “I mean, who are you _really_? You talk about these crazy things like they’re normal, and you understand each other.”

There was a pause.

“Yeah,” the Doctor drawled. “That’s… complicated. Eliot, what kind of resources do we have here? All you need to know now is that there is an incredibly deadly plague waiting to happen in the Vivarium, and Troy is the carrier.”

Eliot swallowed. “So… what? We—destroy it?”

The Master grinned. “I like the way you think, Blondie.”

The Doctor tugged at his own hair, which was slightly difficult to do around the screwdriver still in his hand. “Contain it. If we can contain it—”

“We’ve compromised quarantine,” the Master said. “It’s time for destruction.”

The Doctor scowled at him and started pacing, which was difficult given their arrangement. On the second about-face upon reaching a wall, he saw that the Master had lifted his free hand to his temple, wincing heavily. As naturally as he could manage, the Doctor transitioned to searching their surroundings again. They needed to get out of here and get back to working on the underlying problems, on the larger picture, on what could be a small but glorious return from the brink of extinction. They weren’t alone, and that in itself was something.

The Master had set his jaw, and he was suffering behind blank eyes by the time the Doctor started opening crates and boxes, all of which seemed to contain medical equipment or janitorial gear.

“After we’re done here,” the Doctor remarked, watching him, “we should head back to Earth. Take a vacation. Someplace scenic.”

“I’d be recognized,” the Master said tonelessly. “Britons would ask for my autograph. And/or casual sex.”

The Doctor made a point of looking him up and down. “We could disguise you. We could bleach your hair.”

The Master bared his teeth, and the Doctor gloried quietly in the flare of life. “ _No_ ,” the Master hissed. “Never again.”

“It wasn’t my fault,” the Doctor insisted, fighting with a grin. “I was a natural blond; I didn’t know how to do it.”

“There are mistakes,” the Master said, “and then there are crimes against the species. My mother almost killed me.”

“Once she stopped laughing,” the Doctor noted.

“That wasn’t laughter,” the Master told him. “It was hyperventilation.”

“It’s a thin line,” the Doctor said.

The Master snorted. “About as thin as the asteroid belt.”

“The asteroid belt is thin in spots,” the Doctor said.

“So’s your logic,” the Master replied.

The Doctor opened another cardboard box blazoned with the Vivarium logo—a miniature planet cradled by a stylized _V_. This one held a few different chemicals for the laboratory, and he pushed it aside.

“You could help,” he remarked.

The Master frowned. “This is your job. I break things, remember?”

The Doctor stopped in his search, planting both hands on the edge of the latest crate (plastic buckets and a cleaning solution so volatile it had been outlawed in one galaxy) to look the Master in the eyes.

“If this planet dies,” he said deliberately, “we die with it. And even if we somehow manage to escape when we regenerate, I will _never_ take you to the world premiere of the first episode of ‘Teletubbies.’”

The Master scowled at him for a long moment, but then he jerked a box out of the stack and pried it open.

“If you put it that way,” he muttered, “how can I refuse?”

“…‘Teletubbies’?” Eliot asked faintly.

“A staggering work of illuminating genius,” the Master explained.

“So—so these… Vashy… things…”

“Vashta Nerada,” the Doctor corrected idly.

“Yeah,” Eliot said. “Those. Where did they come from?”

“I imagine whoever is in charge of this place seeded the Vivarium with larvae.” The Doctor scanned for a box that contained something metal, but when he pulled one out, there was nothing in it but a microscope. “Then Miss Lee’s enzyme stimulant accelerated their growth—presumably faster than the organizer intended—and today they hatched. I assume they were meant to grow unnoticed, and they were to be fed with all those live animals we happened on. If they’d done their maths right, it might’ve worked rather nicely.”

“How can you kill a Vashta Nerada?” Eliot asked.

The Master had found a long lighter and was playing with the trigger. Of _course_ he would be a pyro. The Doctor took the thing away from him and shoved it into a pocket for safety’s sake.

“I… don’t know,” he admitted. “They didn’t really brief us on that sort of thing at the Acade…”

He stopped, looking down at what appeared to be a large hamster ball.

“Oh,” he breathed.

This could be bad—this could be terrible—but it wasn’t worse than falling into shadow. It wasn’t worse than the obliteration of Poltiro and maybe more, than seeing Eliot’s life snuffed out, than another lost battle on his long, long list. It wasn’t worse than dying here, even if that wasn’t forever, right after he’d finally summoned a bit of bright light to the Master’s distracted eyes.

The Doctor took a deep breath, held it, and let it go.

He found the chemicals, the abrasive cleaner, the plastic ball, and a pair of safety goggles and laid them out in a line, placing the lighter at the end. Then he swallowed hard, unlocked the handcuffs, and dropped them beside the other objects that might have been their salvation now.

The Master was watching him closely, eyes half-narrowed and intent. The Doctor met that gaze, part suspicious and part accusatory though it was, and then drew his screwdriver and added it to the row.

“Master,” he said. “I need you to improvise the most powerful explosive that you can.”

Silence. The Master had been rubbing at his wrist, but he went completely still.

“Have Eliot help you,” the Doctor said. “I’m going to try to lead Troy away from you to buy some time. If I can’t find my way back here within fifteen minutes to assist you, you’re going to go to the terrarium and ignite as much of it as possible. Stay out of the shadows.” He mustered a smile. A TARDIS wasn’t built to translate Gallifreyan, because the owner of one wasn’t supposed to need it. “ _Good luck_.”

He wasn’t sure why he hesitated, standing there watching the Master look from one item to another and then, incredulously, up to him. But it meant he was still there when the Master lunged forward, buried both hands in his hair, and kissed him wildly, ferociously, with a resonating hunger and need and possession, with just a fragment of apology. A few critical parts of the Doctor’s brain melted, and his insides went embarrassingly wobbly. He was, as the Master sucked on his bottom lip and slid soft fingertips around the curves of his ears, fast discovering another reason Lucy Saxon had chanced everything on a man who did not exist.

The Master drew back and immediately focused his attention on the materials at hand, and the Doctor didn’t dare to look at Eliot. He cleared his throat once, and then twice, and then gave up and ran.

He was running towards the Vivarium, ready to offer himself as bait, but he was also running to keep ahead of the tide of memories cresting at his heels—things suppressed and submerged and crushed down in the vain hopes that he had the power to forget, and denial had the power to erase.

He recognized a flickering fluorescent light they’d seen before. He was getting close, and the past was catching up.

 _“Theta…”_

 _“Just a minute.”_

 _“It’s important.”_

 _Theta snorted and winked. “More important than the ancient origin of the Judoon? Can’t be.”_

 _But Koschei looked serious—grave, even. Almost a little scared._

 _Theta tossed the textbook aside, ignoring the way it crumpled a few of its own pages as it hit his pillow, and went to Koschei, taking both his hands._

 _“I’m listening,” he said, smiling gently for good measure. “What is it?”_

 _Koschei smiled back hesitantly, searching his eyes, squeezing his fingers, a tremor coursing through his shoulders and down his spine._

 _“Theta,” he said, so softly it was hard to hear, “will you—will you marry me?”_

 _This was so much like the time two summers ago that Koschei had pushed him into the manor’s freezing lake that Theta thought for a long moment that he was having a flashback. His lungs were empty—all of him was empty; he was carved out and cavelike, nothing but a lace of crystallized ice to line his skull, to fill his chest._

 _“Kosch, that’s forever.” He choked on the last syllable._

 _Koschei’s grip on his hands was cutting off his circulation. “Of course it is, stupid.”_

 _“No,” Theta insisted, “it’s really_ forever _. Because we’re going to last forever, or near enough.”_

 _“I know that.”_

 _“But what if—what if something happens, and one of us regenerates? Or both of us do? Or what if we just—change?”_

 _Koschei’s smile was small and warm and horrible, because it fell like lead into the pit of Theta’s stomach. “I’m not going to change. Not unless you tell me to, remember?”_

 _“But your family—”_

 _“I’ll talk them into it.”_

 _“But what about—” Theta couldn’t breathe. What about the universe? What about the stars? What about endless expanses of nothing and clusters of life and people and progress? What about thousands, millions, billions of places they’d never seen? What about the wide-open anything the TARDIS meant, and the innumerable possibilities, and the travel and the discovery and the dreams made realer than any imaginary detail?_

 _What about the only thing Theta had ever wanted as much as Koschei?_

 _“I love you,” Theta said, and it felt like drowning. “You know that. I always have. That won’t change.”_

 _“Then what’s so wrong with forever?” Koschei asked, smiling and then grinning and then beaming, and then catching Theta in a suffocating hug._

 _“Nothing,” Theta whispered, curling his fingers in Koschei’s hair, which was dark like a deep night’s sky without the stars._

The Doctor scrambled around a corner, darting out of the shadow of some shelving, and kept on running.

And then he swerved around the next turn and found himself a corridor away from a neat package of predator.

Troy’s sightless visor turned towards him—that was interesting, the indomitable scientist within him observed; were Troy’s residual instincts influencing the parasites?—and the Doctor planted his feet and raised his chin. It wasn’t too unlike that time with Billy the Kid when they’d… well.

The suit swiveled fully, and it cocked his head again.

“Notice anything?” the Doctor called. “Time Lord. You want food? I’ve got a dozen lives. I’m a feast. Smell it, don’t you? Others have.”

“F… feast,” Troy’s voice repeated haltingly.

“That’s right,” the Doctor said, wiggling his fingers where his hands hung at his sides. “Come and get me.”

The layer of darkness in Troy’s helmet receded quickly, revealing the flayed, fleshless skeleton beneath. The Doctor clenched his teeth and watched as the Vashta Nerada poured their energy into the extra shadow at Troy’s feet, stretching it forward down the hall, blanketing the muted tiles. The Doctor waited, and waited, and let the Troy-shaped tendril draw closer to his half-turned trainers, poised to run.

When the carnivorous menace was half a meter from his toes, extended thinly over the length of the corridor, he spun on his heel and bolted, not without a parting shot: “You’ll have to try a bit harder than _that_!”

Making sure to slow down at corners, giving the Vashta Nerada plenty of time to track his route and follow, the Doctor jogged through the tangle of halls, inwardly cursing their architect for the umpteenth time. He was _relatively_ sure he was leading the creatures progressively further from the Master’s makeshift explosives lab, but educated guesses didn’t look like much when juxtaposed with certain death.

Why was it always certain death? Couldn’t he have had fifty-fifty death for once?

All the same, the Doctor’s educated guesses were generally sound, and today they were fortunately serving him well. He’d left the storerooms far behind, which he figured gave him leave to speed up a little and put some distance between him and the ravenous shadows scenting for his blood. He would just have to be careful that he didn’t end up too close to the compound’s primary entrance, the front wall of which was composed almost entirely of tall windows—a pretty feature and a pretty way to release Vashta Nerada into the air, the larger planet, anywhere they could stow away to from there. He just had to avoid the lobby, and they’d be off to an acceptable start.

The Doctor knew many things. One of the things he knew was that you didn’t generally avoid things by walking directly into them.

“Hell,” the Doctor said, lacking the breath or the patience for eloquence.

“Hello?” a voice asked in answer.


	3. Part III

**Notes for the Chapter:**

> Thank you for reading. <3

Moving past the front desk, every hair on the back of his neck (and, knowing _his_ hair, everywhere else it grew) standing up to remind him what was close behind, the Doctor discovered a small cluster of terrified scientists, Kate Lee at their head.

“What are you doing here?” he demanded desperately. “Don’t you know there’s a… quarantine…”

Of course.

“Apparently they assumed it’d start with us,” Kate explained, no small note of bitterness in her tone. “We only just broke out of the lab and made it here.”

“ _Get out_ ,” the Doctor said. “We’re all dead if it finds a proper meal. There has to be a—”

He turned to the desk, leaped over, and reached for his screwdriver to override the deadlock on the front doors.

No screwdriver. Right. The old-fashioned way it was.

Jamming his fingers into all the buttons to no avail, the Doctor suddenly understood the struggles of ordinary people faced with inimical technology.

“Right, then,” he said, straightening his tie and sliding back over the counter. “The _really_ old-fashioned way.”

It wouldn’t be the first time he’d thrown a plastic chair at a sheet of glass, and it probably wouldn’t be the last.

It was, however, the first time the chair had bounced off and narrowly missed a collision with his head before clattering to the floor.

“Right,” he managed when the gasps of surprise had mostly quieted. “Everyone empty your pockets.”

Given that he was trapped with a group of top-secret scientists—the geekiest variety of being in the universe, with the notable exception of Time Lords—the Doctor was expecting a slightly more impressive yield than half a dozen paperclips, bus fare, seven different sets of keys, seven mobile phones, and a laser pen.

“ _Think_ ,” he ordered his brain, smacking his skull for good measure. “Must be something we can…”

Slow, staggering footsteps echoed from the nearest hall.

“Kate,” the Doctor said sharply, “barricade that door. Don’t let that thing get near you, and do _not_ let it get in. Stay in the light. _Hurry_.”

She nodded, jaw set, and recruited a bespectacled brunette to help her block the door with chairs, which at least would be serving a purpose after failing as projectile weaponry…

Bespectacled.

The Doctor snatched the laser pointer, scrambled behind the desk one more time, and whipped out his glasses. The lenses had been made on a small planet that had, sadly enough, burned to a cinder—its glass industry had been the focus of the entire world, and when insufficient safety standards led to a primary factory catching fire, the capital city was gone in a day. Overpopulation, low surface area, and arid weather had taken care of the rest, and only the deserts that had once fed production were left behind.

But it was nice, having a time machine. You could pick up a prescription so responsive that the manufacturers had received warnings from a few anti-telepathy watchdog groups, a prescription that could magnify at a variety of levels and degrees depending on what you were looking at and the angle of your head.

The prescription in question was currently concentrating the light of a laser pen, rather neatly changing it from a pointer into a cutting device making short work of the locked door controls.

Catching the tip of his tongue in his teeth, the Doctor cut carefully through the steel plate protecting the main workings, tilting his glasses to aim the laser’s trajectory.

The steel plate was actually doing a rather poor job of shielding its sensitive components, and the laser sliced through them as well, cleaving wires indiscriminately. The Doctor glanced up to see how Kate was faring with the door—she and the others seemed to have constructed a barrier that looked, unsurprisingly, a bit molecular, but whether it would hold was a question… that the Doctor could not afford to speculate about just yet.

He shoved the glasses up into his hair and tucked the laser pen between his teeth, prying sections of steel back to access the guts of the controls, wires spilling out like multicolored spaghetti into his hands.

The laser had made an extremely clean cut despite its slideshow-presentation-ready size, which made it possible to reconnect wires as he pleased. The Doctor routed power away from security and into what looked like an electronic hub, linked a few other interrupted wires, and watched the console light up like a Christmas tree, gifts and all.

This time, when the Doctor slapped a button that looked promising, the front doors parted and shuddered open with a whine.

A cheer went up among the scientists, but over it, the Doctor heard a banging at the other door.

“Get away from there!” he shouted to Kate. “Get out, go! Go home, turn on all the lights—”

“What about you?” Kate asked, edging towards the exit as her team poured out and fled.

The Doctor winked. “Did you really think I was a health inspector?” he said.

He let Kate’s imagination do the rest. When she’d raced out the door behind the others, lab coat fluttering, the Doctor shut the doors again, rearranging the wires so that they’d stay that way for now.

In typical fashion, just as he repaired the last connection, the barricade of chairs broke, scattering inward, and Troy’s suit lumbered in, shuffling through them where they lay.

Troy was so bulky—and his shadows were so ambitious—that trying to slip through the door would have been a lost cause. The Doctor was going to throttle whoever had designed this place.

And he was going to kiss the Master again the next chance he got.

He jerked his glasses free of his tangled hair, aimed the laser pen at the ceiling through them, and deftly outlined a large square. The panel slammed to the counter in a burst of plaster dust, and the Doctor grabbed one of the chairs, steadied it on the countertop, and climbed up on it, the better to vault up into the ceiling and cut his way into the air vent.

Throwing a sheet of aluminum at the Vashta Nerada—which hit the suit directly in the head with a tremendous clang—probably didn’t hurt either.

Crawling through the ventilation shaft was slower than the Doctor had hoped and significantly louder than he’d expected. As well as being painful, given that he banged his shins on nearly every upraised juncture between segments, the whole process just made a magnificent racket, though at least he could peer down through periodic gratings into the rooms he was passing over. On the upside, he had a bit of a better feel for the layout by now. On the downside, the noise meant that he was leading the Vashta Nerada directly to Eliot, the Master, and their last chance.

The Doctor had always figured that you won some, you lost some, and with some you couldn’t tell until the smoke had cleared.

He glimpsed a navy blue boilersuit and a puff of blond hair through the next grate, called a warning, and kicked it out. He was following it to the floor almost before it had landed, wincing heavily as he caught himself—even Time Lord joints weren’t _quite_ built for the abuse he put his through.

“Come on,” he told them, panting. “Time to go. Now.”

“Don’t get your knickers in a twist,” the Master muttered, his nose centimeters from the scraps of metal he was welding with the screwdriver, which couldn’t be good for his eyes. “Give me forty-five seconds.”

“You have ten,” the Doctor said.

“Twenty.”

“This is not a negotiation!” The Doctor shot a desperate look at Eliot, who was holding an industrial lantern above the table, tilting the shade to illuminate the Master’s work.

“Good thing I’m fucking brilliant,” the Master said, popping the screwdriver into the corner of his mouth and slotting the latest piece into the intricate machinery he’d assembled in the plastic sphere. “Brilliant enough to walk, chew gum, and build explosives all at once.” He slipped the screwdriver over his ear instead, snatched up a few more crafted fragments of metal and who-knew-what, and hefted the sphere, which had almost started to resemble— “Remind you of anything?”

The Doctor gave him a black look, plucked the screwdriver free without touching the Master’s skin, took the lantern from Eliot, and shouldered through the door.

He was less surprised than he would have liked to see the hulking figure of Troy’s suit at the end of the hall.

“Go!” he barked at the Master, who was fiddling with a wire in his device, Eliot hovering not far away. “Straight towards the Vivarium, and keep _out_ of the shadows!”

“Your knickers,” the Master said, striding past him, “are in a sailor’s knot.”

“You’d know, wouldn’t you?” Eliot asked, mustering a white-faced grin as he led the Master around a corner, grabbing his elbow to guide him as he worked. “I mean—you and he—” The Master laughed, and the sound was bright and delighted and harsh.

The Doctor looked into Troy’s hollow eye sockets, because if the dead man’s habits had made it through to the Vashta Nerada, it would mean something to them, too.

“This ends here,” he said.

“Here,” the comm repeated, Troy’s voice distorted and gravelly.

“Well,” the Doctor said, watching the shadow crawl over the tiles towards his feet. “Down the hall. But you get the drift.”

“Dr…”

“Ciao,” the Doctor said, and for the millionth, the billionth time, he ran.

He caught up to Eliot and the Master within moments, as the latter was still toying with his latest brainchild—which the Doctor could only hope was as elegant as its predecessors. Everything was at stake. The Master would have given his all. It was the only explanation that made sense, the only explanation that would save them, and therefore the only explanation the Doctor could accept.

And then they reached the section of corridor with the flickering light—except that the light had stopped flickering and gone out.

Skidding to a halt, the Doctor flung an arm out in front of each of his companions, stopping them before they trespassed into the dark.

Eliot was so pale the Doctor worried he’d pass out. “So—so any shadow could be full of—of—”

“Invisible piranhas,” the Master finished calmly, taking advantage of the reprieve to twist carefully at a portion of his creation.

“I hate my life,” Eliot said faintly.

“Join the club,” the Master muttered. “We’ve got T-shirts and little hats.”

“Honestly,” the Doctor spared the breath to say. Then he raised the lantern in one hand and the screwdriver in the other, feeding sonic energy into the battery, and flooded the bulb with additional power until it sparked and stuttered and blazed like a beacon, filling the hall with blinding light.

Eliot and the Master skipped off again, so at least there was that—the Doctor spun, the flaring lantern raised, as Troy rounded the corner to follow them.

“Catch me if you can,” he whispered, and he flung the light at his adversary, whirling on his heel without waiting for the smash of glass or—hopefully—the catching of a flame.

The Master seized the screwdriver the second the Doctor breached the control room, applied it to a large circuit in the heart of his device, and then handed it back, snapping the plastic shut.

“There,” he said, contentedly, and the Doctor wasn’t sure whether to be proud or horrified. Both sounded like a fair bet.

Eliot was pressed up against the consoles, watching the hall from which they’d come, and the Doctor could already hear footfalls and the feedback from the comm. It was countdown time again.

“We need to get it into the Vivarium,” the Doctor said, gesturing back, “and burn as much of the forest as we can—preferably all of it. Important question,” he remarked to the Master, and his voice obviously wasn’t shaking in the slightest, because he was a Time Lord, and he knew this part. “Is that thing going to work?”

The Master grinned. “Don’t you trust me?” he asked.

Whether the Doctor did or not was inconsequential, because he didn’t have a choice.

He slammed his fist down on the button that operated the control room’s lights, maximizing all of them, and Eliot hid his face. The Doctor darted over to the door to the Vivarium and smacked that button, too, steel swishing softly at his back as he retreated blind, watching the silhouetted suit approach.

“Come on,” he bid the Master and Eliot one more time. “Stay in the light from the window; _come on_. It won’t follow unless we’re all here—”

“St… starving…” Troy’s voice murmured, and his feet carried ravenous death closer still as Eliot and the Master squeezed past the Doctor and out onto the Vivarium’s soil.

“Stay in the light,” the Doctor said again as the three of them spread out over the open space before the trees. He kept one eye on the shadows near his toes, at his back, seeming to draw towards him every time he swung his arms—and trained the other on the familiar figure with its familiar gait, making a familiar slow and inescapable advance.

The Doctor decided, rather belatedly, that this was not one of his better on-the-spot plans. Thinking about it, the entirety of the day so far had been one on-the-spot fiasco after another, and he had the sneaking suspicion that this bit was about to get worse.

“Oh, God,” Eliot whimpered, getting his first good look at Troy’s skull as the suit staggered into the Vivarium, where it paused. “Oh, _God_. Troy—he’s a _person_ ; he gave me the tour—”

“Leave it,” the Master cut in sharply. “Later you’ll have time.”

Troy’s suit shuffled forward, dual shadows wavering, the unnatural one panning slowly over the ground, reaching for something new to kill.

“Triangulate,” the Doctor instructed, keeping his voice low. “Spread out, but stay—”

“In the light; we _know_ ,” the Master hissed back, clutching his sphere to his chest now, edging towards the wall. The Doctor recognized that tone, and he recognized the suppression of the genuine fear. “Eliot, circle around towards the Doctor and—”

Out of the corner of his eye, the Doctor saw Eliot shift and sidle nearer, and then the boy’s ensuing scream made his ears ring.

The Doctor turned in time for the splash of blood as Eliot jerked away from the dark, clutching at his right hand, red splattered down his suit, flecks of it on his face.

Eliot stumbled, cradling his hand to his chest, gasping for breath, and his eyes were wild. The searing light from the control room gleamed on the tears of helpless pain that were swelling in his eyes, and he swayed on his feet, dangerously close to the shadows yet again. The Doctor threw an arm out towards him.

“Eliot—”

A white streak at the side of his vision resolved into the Master, who shoved the bomb into his hands, wrenched the screwdriver from his grip, and seized a fistful of Eliot’s sleeve, then hauled him back into the control room, knocking the Doctor forward.

“Thanks,” the Doctor gasped, hugging the sphere-bomb—that was a new one—and fighting for his balance, dirt spraying around his trainers as he reeled towards Troy and the swathes of darkness.

“Right,” the Master said, aiming the screwdriver at Troy’s comm and pressing his thumb down hard. “Sorry.”

The comm fizzled and then burst open in a shower of sparks, charring the suit and sabotaging enough of its functions to give the Vashta Nerada pause as their method of mobility rapidly failed.

Over the sputtering of fried electronics, the Doctor heard a ripping sound, and then a persuasive call broke into his mesmerized observation.

“Doctor! _Throw the damn thing_!”

Without a thought, his mind a broad white blank, the Doctor hurled the sphere out into the Vivarium, plastic winking as it sailed above the trees.

“Now _get in here_.”

It was only when he had slipped back into the control room—only after the Master had slammed a shoulder into the button without even faltering as he wrapped a strip of his shirt tightly around the two bleeding gaps on Eliot’s hand; only after he’d blinked hard and shaken his head—that the Doctor realized that the Master’s orders had been laced with hypnotism, and he’d been powerless to disobey.

“ _Never_ ,” he hissed, “do that to me a—”

“Why am I not hearing a seismic explosion?” the Master asked, voice taut, as he knotted the frayed strip of cotton, and Eliot sobbed once.

“I guess you built the bomb wrong,” the Doctor snapped. He couldn’t _believe_ … after all he’d done, all the chances he’d taken, all the careful baby steps over lava and acid and the poisoned spikes of the past, the Master had the gall—the disrespect—the _disregard_ to treat him like another tiny human, another minion, another creature of no consequence, to be hypnotized, manipulated, and tossed away. It was an invasion—a _violation_. It was sick and cruel and disturbing and simply ungrateful after all the things the Doctor had parted with, after all the sacrifice not only of others’ approval but of his own faith in his moral decisions. His actions since that last—and technically first—day on the _Valiant_ had begun to skew the principles that had guided the entirety of nine centuries of his life, nine centuries spent gutting and butchering his dignity, carving himself up for no better reason than because this man asked for his soul in smaller pieces—

The Master spared him a sneer and strode for the console, squinting out. Eliot’s blood was wet on the Master’s torn shirt and smeared all over his hands, and the obvious metaphor made the Doctor feel so very, very old. “Only you could make an explosive fail to detonate the one time you _want_ it to.”

Attempting to ignore him, the Doctor spread his hand over Eliot’s hardworking single heart and searched the agonized dark eyes, making sure the poor kid was still responsive before joining the Master by the computer screens, everything else aside.

“I did what you told me,” the Doctor responded, voice clipped. “This one’s on you.”

The Master glared through the glass at the thin trail of smoke rising from the trees. “You didn’t throw it hard enough,” he said. “You’ve barely even started a fire; more chemicals should’ve combined when it shattered.”

“No,” the Doctor said as a cold hypothesis slowly dawned. “It was you. You built it to be ideal for Earth’s air composition, didn’t you?”

The Master’s eyes went very wide, and his hands tightened around his own elbows where he’d folded his arms. The Doctor was just a little too kind to say _Humanity is contagious_.

“You mean to say it’s not flammable enough?” Eliot asked weakly, leaning against the wall. He looked like he could barely keep his head up, and the Doctor cringed as he nodded.

He turned, however, when Troy’s suit, comm still spraying sparks, stumped forward and slammed both fists into the window. The glass shuddered noticeably, and the Doctor instinctively caught the Master’s shoulder and pulled him back.

“They can’t get through that, can they?” the Master asked, watching the suit’s shadows, which the room’s lights cast back against the ground.

“They can if they crack the glass,” the Doctor said grimly.

“’S… reinforced…” Eliot panted.

The suit’s clenched fists descended again, harder still, rattling the pane.

The Master looked past the closest menace to the modest brush fire the failed explosive had begun. It was spreading, by the looks of things, sending up a few billows of oily smoke, but—

“Not fast enough,” the Master muttered, clenching his teeth. He glanced over, trying to twist his grimace into a smirk. “How about that? Not enough time.”

The Doctor curled his fingers around the screwdriver and bent to the controls, avoiding the suit and its thin shadow painted by the Vivarium’s lights from behind. He saw too late that the Master had been holding a hand out to him, one more gesture that he’d missed.

Never enough time. Eternity wasn’t long enough.

“Move,” Eliot said.

The Doctor glanced up as the boy pushed past the Master, holding his mangled hand and the soaking rag to his bespattered chest, and kicked in a glass panel the Doctor hadn’t paid any attention to—one that read _Emergency_. The Doctor’s life seemed to be a series of emergencies, and he couldn’t imagine a fire extinguisher would do much more to the Vashta Nerada than momentarily subdue their growth, if even that.

What Eliot fished out of the shards of glass was not the classic red extinguisher that stood among them, but a small silver cylinder with a few buttons on the side.

“What is that?” the Doctor asked slowly.

Ignoring him, sucking in shallow breaths, Eliot jammed his shoulder into the button that opened the Vivarium door. He hefted the canister in his left hand, gauged the distance with flinty eyes, and then—in the kind of superhuman display the Doctor could never quite become accustomed to—flung his acquisition inside.

And that was the real beauty of mankind, for all the horrors they were capable of, for all the flaws—when the Doctor was one disaster short of giving up for good, a bleeding new-hire employee would find the strength to pitch some last hope along the same trajectory the sphere had traced.

Eliot leaned against the button, wheezing, and the Doctor had darted to him before the door finished sealing.

“What _was_ that?”

Eliot grinned. “Compressed hydrogen,” he said.

With that, he crumpled to the floor, and the Doctor dropped beside him, wrapping both arms around his fragile human body, because—

The explosion rocked the building so hard that the floor rippled like a liquid, and the roar of atoms jarred, jumbled, and displaced deafened the Doctor instantaneously. He curled around Eliot, squeezing his eyes shut against the blinding flare of light, ducking to protect his head from the rain of shredded machinery and shattered glass.

And then someone was holding him, too, tightly, cool skin and soft hair against his neck as the airlock door spared them a quick decimation by explosive fire. The Doctor smelled melted metal, the tang of wrecked electronics, the general charring, the obliterated wildlife, the choking smoke—

The Master was hauling him to his feet and helping him gather an unconscious Eliot into both arms. The Master’s mouth was moving, and the Doctor watched it, but he couldn’t hear a thing over the distant, constant chime in both ears, a soft, faint, pure sound; he pictured a bell rung at the far end of a white desert, gentle dunes and a woman all in black with this single offering, this little gift for him.

The Master curled a few fingers just too tightly in his hair, the pad of his thumb brushing the Doctor’s temple, and met his eyes, shoving the message directly into his brain.

They were so long out of practice that the Doctor’s hearts ached almost as much as his head. It was a jumble of images and fractured syllables, some of them Gallifreyan, some English, some languages that barely had verbal expression at all, but the two of them were still so inescapably aligned that the gist of it came blazing through.

 _We don’t know anything about the structure of this place, and an explosion that size could easily have begun some kind of chain reaction; come_ on _!_

So they ran.

It was giddy—no, it was heady. That was a laugh, or would have been if the Doctor had had the breath for laughter. Sounds were starting to filter back into the his ears; he could hear the massive fire they’d started, the shriek of metal twisting in the heat, the crackling of acres of enclosed vegetation succumbing to the flame. Now that the Master had breached all of the psychic defenses, he’d given up on vocal communication entirely: it wasn’t a bad idea, given the running, but that didn’t make it any less unsettling to the Doctor, who was just _used_ to being alone. Even when he had companions, even when he traveled with friends, his mind was his sanctum, his greatest weapon, and his prison all at once—people didn’t understand. They couldn’t access him. The cost of safety was isolation.

Until now.

They careened around a corner, Eliot’s weight in the Doctor’s arms unbalancing him so badly that the Master had to right him as his trainers slid. Before he had even regained his feet, the Master was bombarding him with images of spruce trees, amber liquid oozing from gaps in their bark.

 _Sappy,_ the Doctor shot back sardonically. _I get it._

The Master snickered and then seized the back of the Doctor’s suit, yanking him out of the way as a jagged portion of crumbling ceiling smashed to the floor, narrowly missing Eliot’s trailing arm.

The most dangerous thing about telepathic communication—some would say the best thing, because it limited such a powerful practice—was the difficulty of censoring the thoughts. Directing a message was easy, but only the most refined of telepaths could transmit a clean, specific word or image; generally, the idea came through a rush of associations, and it was almost impossible for a sender to reserve his emotions as he offered his intellect.

When the Master seethed _Idiot_ , letting go of the Doctor’s jacket and shoving him forward again, all of the urgency reached the Doctor’s mind along with the anger. Beneath it lay a deep, heavy, unmistakable fondness that made the Doctor want to stop moving and beg for another try even if the whole Vivarium complex fell down around them.

The Master threw the Doctor a series of glimpses of an exaggerated version of himself bound at the wrists, blindfolded with his tie, and pleading, and the Doctor cursed himself for always forgetting that the connection stayed wide open until one of them shut it properly.

They clambered over the treacherous pile of beams and broken glass that remained of an office door, and there was a fallen information screen not much further down, reduced to a wreck of spitting wires and plastic shards. The floor began to shake in a way that worried the Doctor a great deal—who knew what kind of energy reserves lay beneath this place, to power all of their systems and all of their technology? Who knew what kind of blast radius they could expect if those sources caught as well?

Eliot groaned, and then his eyes snapped open, and he scrabbled against the Doctor’s chest, his damaged hand dragging a brown-red stain across the fabric of the Doctor’s suit. His eyes focused, and then he managed, “Let me down,” which the Doctor had to admit was a relief—either Eliot had doubled in weight, or the Doctor was getting tired perilously fast.

The Master could latch onto fractions of thoughts, so perhaps that was why he also latched onto the Doctor’s arm, jerking him away from a buckling tile as an undaunted Eliot led the way.

 _Just like old times._ Silver leaves; blood-red grass rippling on the sloping hills; they’d gone exploring in a cave not too far from the Academy, and Theta had stepped on every loose rock, slipped on every patch of damp, encountered every cave-dwelling creature imagination could invent. Fifteen minutes and a good half-mile in, Theta had dropped his blue-glowing lamp into a ravine, and then he’d stumbled at the edge, and it was only Koschei’s quick hands and vigilance that had kept him from following the dwindling light.

The Doctor blinked hard, watching Eliot pick his way through a field of displaced drywall on the floor, and sent the Master a distinct command: _Stop distracting me._ He supported it with a lot of angry faces, and the Master laughed enough to choke on drywall dust.

It had always been a competition, hadn’t it? Even when they had been—even when they—even before, they’d kept score. It hadn’t meant as much, but the Doctor was expecting retaliation, and the Master didn’t disappoint.

The thought was so vivid that he could taste the moisture in the air, faintly tinged with sulfur and then overwhelmed entirely by Koschei’s sweet breath, Koschei’s cool mouth, Koschei’s fingers, Koschei’s hips and Koschei’s tongue. This rock formation had been eons in the making, so ancient that its presence resonated in a Time Lord’s chest—built over millennia by the deposit of minerals as the water dripped, and never before defiled by a pair of teenagers who couldn’t wait to get back out to open air.

Koschei’s hands on his waist, Koschei’s teeth at his neck; Theta’s heels scraped through the dust as he let his head fall back, exposing his throat, clenching his fingers in Koschei’s hair.

Except they weren’t his best boots; they were strange shoes, scuffed and beaten, canvas and rubber, with laces down the front, and he wasn’t Theta, and this wasn’t Koschei, except they _were_ , and the Master’s knee between his legs couldn’t have felt more right—

 _Get out of my head!_ the Doctor howled.

 _You first,_ and the Master laughed aloud.

The Doctor scrambled over the remains of a conference room, the fine wood of the long table scattered amongst the glass from the windows, and did one thing he hadn’t forgotten how to do—he put up walls.

He had stone ones with moats, steel ones with padlocked gates, and barbed wire prickling with an electric charge, all of them thrusting upward into the sky, surrounding and protecting the contents of his mind. He closed himself off, and the psychic connection flickered, fluttered, and went dead.

“ _Hey_ ,” the Master hissed with a sharp intake of breath. He had paused halfway over the broken table, a muddled, mixed anger in his eyes that the Doctor couldn’t interpret without the mental link.

There was a low, low rumble, and then the floor shook harder than before—probably an underground power reserve; natural gas, perhaps, by the way the shock wave blasted through, throwing all three of them to the ground.

The Doctor was up first, dragging Eliot back to his feet, brushing him off, and helping him curl his right arm in towards his chest again.

“Not much further,” the boy was panting, and the Doctor wasn’t sure just who he was trying to encourage with that.

Wordlessly the Doctor sent him on, darting back to shift a rather impressive collection of rubble off of the Master’s legs. When he hauled the Master upright, though, the other Time Lord hobbled, clenching his teeth, and the Doctor wasn’t dumb enough to hope that he was faking it.

At least not for more than a moment.

He slung his arm under the Master’s shoulders, not noticing the way they shifted, not paying attention to the no-longer-familiar glory of a cool body against his, not thinking that this was what he’d had and—perhaps—what he still could.

“…stupidly tall,” the Master coughed.

“You’re just short,” the Doctor said.

Eliot was halfway down the hall, and he glanced back when he reached the end of it, holding the door for them. Through the doorway, the Doctor saw upended plastic chairs and a sea of broken glass, and he knew where they were.

“World premiere of ‘Teletubbies,’” he said, “here we come.”

On his own terms, the Doctor wouldn’t have stopped at the curb—the further they could get from a building with the continued potential to explode, the better, as far as he was concerned—but they were impeded by the rather massive convoy of emergency vehicles clogging up the street.

“What’s all this?” the Doctor asked, staring over the assortment of people and personnel. There were medics, firefighters, police, what looked like a bomb squad—and, talking seriously to a well-dressed man in dark sunglasses, a very determined Kate Lee.

Before he could call to her, she spotted them and ran over, accompanied by half a dozen others of various occupations.

“The Director’s been arrested,” she told them over the sudden hubbub, “for money laundering, among other things; apparently this went deep, and they’d been watching him a wh—oh, my _God_ , what happened to you?”

Eliot mustered a shaky smile. “It’s not as bad as it looks.”

“You’re missing two fingers!” Kate cried. “How could that possibly—come on, just come with me, here—”

She put an arm around him and guided him towards the nearest group of paramedics, who jumped quickly to attention, looking alarmed. For his part, Eliot—who was watching Kate as the wind whipped her dark hair into a curtain of ink—mostly just looked pleased.

The professionals were moving in on what was left of the Vivarium, so the Doctor released his grip on the Master and sat down on the curb. As he stretched his legs out in front of him, the Master deigned to join him, not without a frown.

“What now?” he asked.

“Now,” the Doctor said, “we wait.” He glanced at his companion, discerningly. “You shouldn’t have been able to hypnotize me—at the start, when I threw your bomb. How did you do that?”

“I didn’t do anything special,” the Master said. His eyes followed the ambulance as it pulled away, siren blaring, and he smiled thinly. “You must have wanted to listen.”

The Doctor scratched his head a moment, and then he decided to let that one go.

“What happens to this place?” the Master asked when they’d been silent for a while. “I’d have heard about it if it had spectacularly failed. I keep track of the spectacular failures; I like to research them when I’m feeling bad.”

“I guess they build it back up.” The Doctor chewed on his lip, pretending not to notice that the Master’s focus immediately shifted to his mouth. “In a right hurry, too, if they want their real investors to stay. Kate’ll take care of it. She’ll probably do a whole lot.”

“You have a great deal of faith in a race that still enjoys destroying itself over marginal differences,” the Master remarked.

“You don’t have to believe in humanity to believe in individual human beings,” the Doctor replied. “I didn’t see you disparaging Eliot for his species’ errors.”

“There wasn’t time,” the Master said. “I had an alphabetized list, but I prioritized running for my life.”

“Oh, yes,” the Doctor said sunnily. “Of course.”

The Master pouted, which was a condition the Doctor was almost starting to like.

—

It wasn’t quite half an hour before a few of the firefighters returned from the latest expedition, one of them gesturing to the chief of police. The Doctor had seen this part enough times to know that he’d gotten what he was waiting for.

He stood, pushed his hands into his pockets, and strolled off around the side of the complex towards the collapsed dome, and an irritated Master hastened after him.

“What are you so excited about this time? Did somebody bring a drug-sniffing puppy you feel kinship with?”

“Someone ought to tell the firemen that only Earth police use big blue boxes,” the Doctor said, grinning broadly as he saw the particularly fine specimen rising from the plane of ash. “I suppose they’ll figure it out.”

A glance confirmed that the Master’s expression had veered dangerously close to grudgingly impressed, or at least secretly pleased.

The Doctor smiled and started for the TARDIS, taking out his key. “Could’ve been worse, couldn’t it?”

The Master made a point of contemplating that. “I suppose,” he conceded at last. “You could always have had bad hair.”

The Doctor gave him a long, contented look, tossed the key, and snatched it out of the air. “Right, then,” he said. It was only a few more meters, so he winked at the Master and then took them at a run. “Allons-y!”

“Oh, no, you—”

Shortly, there was a crashing noise, and the Doctor, who had just made it to the console, turned to see that the TARDIS had slammed her doors in the Master’s face.

The Doctor got the feeling that that was going to prove a bit troublesome in the grander scheme of things.

And then he heard something rather strange—something that sounded like tentative patting, followed by the Master’s voice:

“Come on. Please?”

The TARDIS door creaked reluctantly open, and the Master set his jaw and stepped inside.

The Doctor ducked over the console to try to hide his grin.


End file.
